Kai-Fong Lee

• University of Mississippi

Recently, it was shown that a dual- or triple-band patch antenna can be designed by cutting U-slots in the patch of a broadband antenna, and the method was applied to the L-probe fed patch, the M-probe fed patch, coax-fed stacked patches, and aperture coupled stacked patches. All these cases involve either a rather complicated feed, or more than on...

A wide band dual-beam microstrip antenna is proposed in this communication. Two radiation beams off broadside are obtained by operating the patch antenna at the higher order TM02 mode instead of the fundamental mode, which radiates a broadside beam. Broadening the antenna bandwidth is achieved by using the U-slot technique. Unlike previous work on...

A polarization reconfigurable E-shaped patch antenna with wideband performance is proposed in this communication. The antenna is capable of switching its polarization from right hand circular polarization (RHCP) to left hand circular polarization (LHCP) and vice versa. Its structure is simple and consists of a single-layer single-feed E-shaped patc...

The basic geometry of a microstrip patch antenna (MPA) consists of a metallic patch printed on a grounded substrate. Three commonly used feeding methods are coaxial feed, stripline feed, and aperture-coupled feed. The patch antenna idea was first proposed in the early 1950s, but it was not until the late 1970s that this type of antenna attracted se...

Inserting shorting-wall or shorting-pins to microstrip patch antennas is one of the popular size-reduction techniques for mobile antennas [1, 2, 3]. If the shorting-wall or shorting-pin is properly placed, the area of the resonating element can be substantially shrunk to one fourth or even more of the original half-wavelength full size [4]. Moreove...

The general method of using U-slots to design dual- and triple-band patch antennas is described. In this approach, one starts with a broadband patch antenna, which can consist of one or more patches. When a U-slot is cut in one of the patches, a notch is introduced into the matching band, and the antenna becomes a dual-band antenna. If another U-sl...

An adjustable air gap was proposed the resonant frequency of patch antennas. T investigated theoretically and experimentally coaxially fed patch only. The main disadvantag method to tune the frequency of coaxially fed p center conductor has to be de-soldered and r time the width of the air gap is changed. I investigate the air gap tuning of a recta...

Detailed studies were presented for two recent designs of single probe-fed circularly polarized patch antennas with U-slots. In one design, a square patch with truncated corners is used to generate circular polarization, while a symmetric U-slot is etched on the patch to increase the usable bandwidth of the antenna. In the second design, both these...

A single-feed circularly polarized (CP) patch antenna at L-band is designed and built using the recently developed U-slot loaded patch technique. With the presence of the U-slot, the antenna fabricated on a high-dielectric-constant (ε_r = 10.02) substrate achieves a reasonable axial-ratio bandwidth. At the operating frequency of 1.575 GHz...

In this letter, a new design for single-feed dual-band circularly polarized microstrip antennas is presented. A stacked- patch configuration is used for the antenna, and circular polarization is achieved by designing asymmetrical U-slots on the patches. The dimensions of the U-slots are optimized to achieve circular polarization in both bands. A pr...

A new technique to achieve a circularly polarized probe-fed single-layer microstrip-patch antenna with a wideband axial ratio is proposed. The antenna is a modified form of the conventional E-shaped patch, used to broaden the impedance bandwidth of a basic patch antenna. By letting the two parallel slots of the E patch be unequal, asymmetry is intr...

The technique of using U-slots to design dual/triple band patch antennas is applied to patch antennas fed by meandering (M) probes. It is found that the advantage of the M-probe, namely, low cross polarization, is preserved by the use of pairs of face-to-face U-slots. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1498–1504, 2010; Pu...

The U-slot patch antenna was originally developed as a single-layer, single-patch wideband antenna. It has recently been shown that it can also be designed to perform a number of other functions. In this paper, a comprehensive account is given on the development of this antenna. Emphasis is placed on experimental and simulation results for various...

Recently, it was shown in [1] that, by cutting one or two U-slots on the patch of an L-probe fed patch antenna, dual or triple band characteristics can be obtained. This example turns out to be a specific case of a general technique of designing dual and triple band patch antennas: namely, if one cuts U-slots in the patches of a broadband patch ant...

An antenna that is capable of exciting four different kinds of linearly polarized waves by four independent feeding ports across an overlapped frequency band is presented. The four polarizations embrace the x and y polarized waves, which have broadside patterns, and the thetas and phi-polarized waves, which have conical patterns. The antenna can pe...

The bandgap characteristics of several electromagnetic bandgap (EBG) structures are compared, and parametric studies of a wideband uniplanar compact photonic band gap (UC-PBG) structure are carried out. It has been presented that the bandgap bandwidth of the mushroom type EBG structure increases when a lower dielectric constant substrate is used or...

Several single feed truncated corner circularly polarized microstrip antennas with different substrate thickness are studied. It is found that the axial ratio bandwidth could be enhanced considerably when a thicker substrate is used, provided that a U-slot and/or L-probe are used to tune the impedance matching. One of the configurations attains an...

The cross polarization characteristic of rectangular patch antennas exciting the TM01 mode is studied. After reviewing and extending the results for the case of edge fed by a microstrip line, simulated and measured results are presented for the coaxial-fed rectangular patch antenna. It is found that, while the aspect ratio of 1.5 yields the best cr...

A wideband circularly polarized (CP) L-slot antenna single fed by L-shaped feed line is designed. Wideband CP is obtained by truncating one of the corners of the antenna element. This arrangement introduces orthogonal components with quadrature phase difference to excite circularly polarized wave. A bandwidth of 46.5% (2.18-3.5 GHz) is achieved wit...

A wideband circularly polarized (CP) slot antenna with L-slot and L-shaped feed is designed. Wideband CP is obtained by truncating a corner of the antenna element, and by exciting the L-slot with asymmetric L-shaped feed line. This geometry introduces orthogonal components with quadrature phase difference to excite circularly polarized wave. The an...

An antenna that is capable of exciting four different kinds of linearly polarized waves across an overlapped frequency band by four independent feeding ports is presented. The four polarizations embrace the x- and y-polarized waves which have broadside patterns and the thetas and phi-polarized waves which have conical patterns. The x- and y-polariz...

A frequency reconfigurable microstrip patch antenna is presented. It is found that the incorporation of a U-slot in the patch can provide a flat input resistance and a linear input reactance across a wider bandwidth than the conventional patch antenna. By placing a variable capacitor and an inductor at the antenna input, the impedance matching freq...

A wide band patch antenna fed by an L-probe can be designed for dual- and multi-band application by cutting U-slots on the patch. Simulation and measurement results are presented to illustrate this design.

The performance of single feed truncated corner circularly polarized microstrip antennas with different substrate thickness is studied by simulation and experiment. It is found that the axial ratio bandwidth could be enhanced considerably when a thicker substrate is used, provided that a U-slot and/or L-probe is used to effect impedance matching. O...

A dielectric resonator antenna (DRA) made of high dielectric constant substrate is studied. Embedding a higher dielectric disk inside the substrate disk enhances the bandwidth. A narrow slot excites the DRA. Embedded DRAs of different shapes are considered for wideband applications. An eye-shaped DRA made with a circular dielectric resonator disk e...

Wideband stair-shaped dielectric resonator antenna (DRAs) are designed. Wide bandwidths are achieved with one-step or two-steps stair geometries. Cricular and square cross-sections are discussed with two different excitation methods: coaxial feed and aperture coupled. The DRAs are designed in the X-band. An impedance bandwidth (S₁₁<-10 d...

Circularly polarized (CP) dielectric resonator antenna (DRA) subarrays have been numerically studied and experimentally verified. Elliptical CP DRA is used as the antenna element, which is excited by either a narrow slot or a probe. The elements are arranged in a 2 by 2 subarray configuration and are excited sequentially. In order to optimize the C...

A wideband vertical patch antenna (VPA) is depicted, which is devised from fractal antenna technology. By using a dual-Koch loop structure, a wideband VPA with 42% bandwidth and 8 dBi gain at the center frequency is designed and tested. Symmetrical broadside patterns are obtained at the passband.

A wideband vertical patch antenna (VPA) is depicted, which is devised from a single circular vertical patch. Without increasing the projection area, a C-shaped proximity-coupled fed VPA with 40% bandwidth and over 6 dBi gain across entire frequency band is designed and tested. Stable and broadside patterns are maintained across the matching band.

A new dual-band vertical patch antenna for broadside radiation is described. The antenna is fed by a proximity-coupled probe, which maintains the advantages of the original single-band vertical patch antenna, such as small size, wide bandwidth and simple structure. The achieved bandwidths are 7% and 26%, respectively, at the lower and upper frequen...

A single-feed elliptical shape dielectric resonator antenna (DRA) is designed for circular polarization application. The antenna is simple in structure and could be excited by either a probe or a narrow aperture. This antenna excites two degenerate orthogonal modes with 90 degrees phase difference. From experimental studies, the single probe feed D...

This paper presents a modified ground plane design for a circular vertical patch antenna (VPA). The circular-VPA is surrounded by a circular corrugated ground and it has around 10% impedance bandwidth and 8 dBi gain. This design yields a significant reduction in cross-polarization radiation and back radiation levels over a bandwidth in excess of 9....

Dielectric resonator antennas (DRAs) designed for broadband applications and excited by L-shaped probe are presented. The L-probe is housed under an air-filled groove between the DRA and the ground plane. A 32% matching bandwidth (S₁₁<-10 dB) is achieved with broadside radiation patterns. The new structure is constructed from the same di...

In this paper we study the hybrid-ring feeding network, which has the advantages of linear phase difference across a wide impedance bandwidth. It is of practical interest to investigate the performance of hybrid ring feeding network in sequential feed circularly polarized dielectric resonator antenna (CP DRA) sub-array. In this paper, the performan...

Dielectric resonator antennas excited by hook- and 3-D J-shaped probes are studied. The lower part of a cylindrical dielectric resonator is modified into an air-filled cylindrical recess to house the feed. Bandwidth higher than 30% is achieved with the proposed feeding mechanisms. The DRAs are excited in the broadside mode within the matching range...

A circularly-polarized vertical patch antenna is proposed and investigated. The design is achieved by simply adding two small stubs to the vertical patch. The antenna maintains the advantages of the original linearly polarized vertical patch antenna, such as simple structure, small size and wide bandwidth. It exhibits a gain of 8 dBi over a 3 dB ax...

A circularly polarized rectangular stair shaped dielectric resonator antenna (DRA) is presented. The DRA is excited by a narrow rectangular slot and rotated 45° with respect to the sides of the DRA to generate circular polarization. A parametric study of the length to width ratio to optimize the axial ratio bandwidth is given. A 3 dB axial ratio ba...

A wideband perforated dielectric resonator antenna (PDRA) is presented. The effective permittivity of the dielectric resonator is altered by drilling holes into a circular ring lattice inside the DRA. The PDRA is equivalent of having an annular ring with lower permittivity outside the cylindrical disk, resulting in enhanced impedance bandwidth. The...

Wideband printed rectangular slot antennas backed with reflectors for unidirectional radiation patterns are investigated. A U-shaped tuning stub is used to improve the matching. Two different feeding mechanisms are introduced. A rectangular slot excited by microstrip line feed with a U-shaped tuning stub gives an impedance bandwidth of 110% (vertic...

The results of the performance of a cylindrical dielectric resonator antenna (DRA) and a circular printed microstrip patch antenna (MPA), compared at X-band are presented. A test was performed in the far field range inside an ane-choic chamber. A standard gain horn from Narda Microwave was used as the transmitting antenna and the AUT was located tw...

New geometries are proposed for the newly invented vertical patch antenna (VPA) for dual band operation and circular polarization generation respectively. The dual-band VPA maintains the advantages of the singleband VPA, such as small size, wideband and simple structure. For the circularly polarized (CP) VPA, it exhibits a gain of 8dBi over 3dB axi...

The U-slot patch antenna, a single-layer single-patch antenna on a relatively thick substrate $(sim 0.08lambda _0)$ , is a wide-band antenna with an impedance bandwidth in a range of 20%–30%, which is about an order of magnitude larger than that of the regular patch antenna. Recently, it was shown that a half U-slot patch antenna, with half of one...

Dielectric resonator antennas (DRA) are attractive at high frequencies. They can be designed with different shapes, but have the drawback of narrow bandwidths, typically around 10%. A wide range of materials is available to control the size and the bandwidth. One method of excitation is the coaxial probe, which is usually placed inside the DRA. It...

A wideband dual polarized dielectric resonator antenna is designed. A two-step stair shaped DRA is excited through a cross-shaped slot by two orthogonal ports. Microstrip lines are terminated with a U-shaped tuning stub to optimize the matching. Both ports are able to give more than 20% bandwidth. To achieve high isolation, two orthogonal ports are...

A dual tapered meander slot antenna (TMSA) is designed for use as an element in a phased array antenna system for RF and microwave sensors and radar applications. The novel design of dual TMSA element, excited by a coplanar waveguide (CPW) feed, provides a wide band and high efficiency characteristics with 50 Ω input impedance at 10 GHz operating f...

Bandwidths of the coaxial fed and aperture coupled cylindrical dielectric resonator antennas (DRAs) with broadside radiation patterns are enhanced by exciting the HEM_11Δ (1<Δ<2) mode at a frequency close to the HEM_11δ (0<δ<1) mode. Both HEM_11δ and HEM_11Δ modes have similar broadside radiation patterns. Me...

A number of techniques for dual-band or multiband operation of microstrip antennas are available in the literature. This article introduces the operation principles and design guidelines of several popular methods, including the multimode-operated patch, stub-loaded patch, slot-loaded patch, stacked patch, and coplanar patch antenna. Their relative...

With <1% in bandwidth, the first microstrip patch antenna has limited applications, mainly for defense purposes. With tremendous effort dedicated to the bandwidth enhancement of microstrip antennas, they are now becoming the most popular antennas selected for modern wireless communications. This article collects different approaches for enhancing t...

A systematic comparative study on the mutual coupling (S₂₁) between dielectric resonator antennas (DRAs) and microstrip patch antennas is presented. The mutual coupling between two cylindrical probe-fed DRAs is studied for different radius to height (a/L) ratios. It is found that the mutual coupling decreases with the radius to height ra...

A new feeding technique is proposed for the newly invented vertical patch antenna (VPA) for single and dual band operations. The new feeding method reduces the projection area and remains simple in structure and wide bandwidth, while the dual-band VPA maintains the advantages of the single-band vertical patch antenna, such as small size, wideband a...

This letter presents a broadband triangular shaped patch antenna with a folded shorting wall. The effect of the folded shorting wall is studied and a modified patch shape is proposed. A stable gain of 6.4 dBi is found over a bandwidth of 28.1% (for S11<-10 dB). The proposed antenna exhibits 48% area reduction and 34% bandwidth enhancement when comp...

An ultrawide-band coplanar waveguide (CPW) fed slot antenna is presented. A rectangular slot antenna is excited by a 50-/spl Omega/ CPW with a U-shaped tuning stub. The impedance bandwidth, from both measurement and simulation, is about 110% (S11<-10 dB). The antenna radiates bi-directionally. The radiation patterns obtained from simulations are fo...

This paper reviews the use of shorting pins to achieve various performance characteristics of microstrip patch antennas. First, appropriately placed shorting pins can be used to tune the resonant frequencies of a rectangular patch antenna and to control the separation of a dual frequency rectangular patch antenna operating in the TM01 and TM03 mode...

Microstrip antennas have the advantages of low profile, light weight and ease of fabrication. However, they have narrow bandwidth and relatively large size in the microwave frequency range. One design which gives wideband operation is the U-slot patch. Applying shorting wall and shorting pin techniques results in further improvements (Guo, Y.X. et...

Broadband DRA using a narrow slot aperture coupled to a microstrip line feed are presented. Two different shapes of dielectric resonators tapered in a stair-like structure have been designed for wideband applications. The resonators are located at the center of the rectangular slot and are excited by a center feed microstrip line. Two flipped step...

The paper describes a new geometry of antenna, to be referred to as the vertical patch antenna (VPA), which can occupy less space and yield wider bandwidth than traditional patch antennas. A circular-VPA ,with radius 0.186λ₀, is presented; it has 10.7% bandwidth and 8 dBi gain. Stable and broadside patterns are maintained across the oper...

Microstrip antennas offer a number of attractive advantages and some designs enhancing the bandwidth were proposed in the literature, such as adding parasitic patches, or using L-shaped probe coupling. Techniques of shorting pin and shorting wall are used to reduce the patch size or to get good matching in the structures. In this paper, a folded sh...

A wideband aperture coupled flipped staired pyramid shaped DRA is presented. An impedance bandwidth of 62% (S₁₁<-10 dB) is measured. The proposed DRA has a stable broadside radiation pattern across the matching band, with an average gain of 6.5 dBi. Simulation results obtained from Fidelity give good agreement with measured results.

A trapezoidal short-circuited patch excited by a hook-shaped probe is designed to achieve a wideband performance. The antenna achieves 45% bandwidth with around 4.0-dB gain. The computed reflection coefficients and radiation patterns are computed and verified experimentally. The main beam of the patch is tilted by about 60° from the broad side. A l...

This paper presents measured and simulated results for a wideband, low-profile patch antenna. A low-profile (0.026λ0) rectangular-shape patch antenna with two shorting pins and two probe feeds is studied. By exciting one port and terminating the other port by a 50Ω matched load, an impedance bandwidth of as much as 69% is achieving for this antenna...

In this paper a printed dipole antenna and three slot antennas are designed to operate at 10 GHz for use in radar systems. A parametric study of each antenna and comparison between their radiation properties including return loss, bandwidth, directivity, efficiency and radiation patterns for 6-element linear array are introduced. Slot antennas show...

A rectangular shorted patch is designed to achieve a wideband performance and size reduction. The patch size is reduced to 25% of the full size patch with over 30% matching bandwidth. A hook shape probe excites the patch approximately. The effect of hook parameters is investigated. A comparison between the L-shape and the hook-shape probe is given....

A half-sized U-slot quarter-wave patch antenna is

A new geometry of antenna, referred to as the vertical

The various aspects of a unidirectional wideband slot aperture antennas that prevent back radiation and make the radiation unidirectional are discussed. The rectangular slot is printed on the ground plane and is excited by a 50Ω microstrip line with a U-shaped tuning stub at the back of the substrate. The backlobe radiations due to the aperture and...

The characteristics of a rectangular-loop fed patch antenna with radiation patterns similar to a 2 × 1 monopole array are presented. The loop is equivalent to a L-probe with the end shorted to ground. The proposed antenna consists of two patches which are excited by two rectangular-loops respectively. It is designed to operate at both GSM and PCS b...

In this paper, the input impedance and radiation properties of the L-probe fed thick-substrate patch antennas with finite ground plane are studied using the finite-difference time-domain method. For validation, the theoretical predictions are compared with measurement. Good agreement is obtained. Initially, the effects of ground plane size are inve...

In this paper a printed dipole antenna and three slot antennas are designed to operate at 10 GHz for use in radar systems. A parametric study of each antenna and comparison between their radiation properties including return loss, bandwidth, directivity, efficiency and radiation patterns for 6-element linear array are introduced. Microstrip slot an...

This paper presents a novel bandwidth enhancement technique by using shorting pins. A low-profile rectangular-shaped patch antenna with three shorting pins is presented. The impedance bandwidth of the proposed antenna achieves 33% (SWR < 2) while the overall thickness of the antenna is only 0.06λ0. The antenna has two close resonant bands. The lowe...

First Page of the Article

A small size antenna is designed for dual-band operation for personal wireless communication systems. The design is based on a tapered meander slot in a finite size ground plane, with a microstrip feed line at the opposite side of the dielectric substrate. The antenna supports 1800 MHz and 2400 MHz operations simultaneously with bandwidths of 130 M...

Several designs for small-size wide-bandwidth microstrip antennas are examined through simulation and experiment. Designs are presented based on two wideband patch antennas: the U-slot patch antenna, and the L-probe-fed patch antenna. Several techniques are utilized to reduce the resonant length of these wideband microstrip-patch antennas: increasi...

The design and radiation characteristics of a wideband quarter-wave patch antenna with shorting pin are presented. By the introduction of a shorting pin to the quarter-wave patch antenna with air substrate thickness of 0.08λ₀, the antenna impedance bandwidth can be increased from 6.4% to 20.7%. The far field radiation pattern has a maxim...

A broadband T-probe proximity-fed short-circuited quarter-wavelength rectangular patch antenna is proposed as one possible candidate for mobile communication applications. Using a foam layer of thickness ∼0.09λ0 as a supported substrate, an impedance bandwidth of 59% and a gain of over 4.5 dBi have been obtained. The far-field patterns are stable a...

Antenna designs are achieved for wideband operation by the use of a coplanar patch-slot antenna, fed by a coplanar waveguide. This design is easily tuned to operate at 2.45 and 5.75 GHz, with wide bandwidth for wireless systems. The operating frequency is controlled by modifying the patch dimensions. The return loss, input impedance, radiation patt...

[1] In this paper, the finite difference time domain method is employed to analyze the T-probe-proximity-fed rectangular patch antennas. With a supporting foam substrate of thickness around 0.1 lambda(0), the patch antenna has shown a bandwidth (SWR less than or equal to 2) of 40% and an average gain of 7 dBi. Numerical results for the input impeda...

A wideband and dual-frequency quarter-wave U-shaped patch antenna with two unequal arms on FR4 substrate is presented. The U-shaped patch antenna is fed electromagnetically by another coaxially-fed patch on the same layer, which operates at a higher frequency band. In this paper, we first proposed a new technique to obtain two closely staggered res...

There have recently been extensive studies of small-size microstrip antennas. Some of these small antennas maintain gains of 5–6 dBi, whereas others have gains of 0–1.5 dBi. One important antenna parameter is the radiation efficiency. There have been very few studies on this parameter for small microstrip antennas. This letter presents measurements...

A broadband dual polarization patch antenna double fed by an L-shaped probe and a near-resonant aperture is presented. The proposed antenna achieves a 1.5:1 standing wave ratio bandwidth of >20% at the two ports. Input isolation exceeding 25 dB has been obtained in the wide bandwidth. Thus, it can potentially be used as a base station antenna for c...

Although the microstrip patch antenna has a number of advantages such as low-cost and light weight, its physical size is quite large at low microwave frequencies. The designs of multilayer miniature patch antennas with coaxial feed are presented. The first design is a rectangular two-layer patch antenna. Measured results and the results of a prelim...

The characteristics of ordinary loop antennas are well known. This paper explores methods to reduce the physical size of printed rectangular loop antennas by introducing a ground plane into the structure. With the introduction of the ground plane into the antenna structure, the relationship between the dimensions of the modified loop are explored t...

This paper presents a set of coplanar patch antennas (CPA), designed to operate at a center frequency of 10 GHz with very wideband characteristics. The antenna is based on a rectangular patch surrounded by thin slot, and its performance is tuned by using slots, shorts, and by mitering the sharp edges and corners. These antenna parameters which incl...

The characteristics of ordinary loop antennas are well known. This paper explores methods to reduce the physical size of printed rectangular loop antennas by introducing a ground plane into the structure. With the introduction of the ground plane into the antenna structure, the relationship between the dimensions of the modified loop are explored t...

Simulation results for a small-size probe-fed notched patch antenna with a shorting post are presented. The area of the patch has been reduced by 94%, while the antenna maintains a bandwidth of 13.2%. The antenna can be designed to operate in the dual-band mode. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 377–379, 2001.

Wideband T-probe proximity-fed regular circular and compact semicircular patch antennas are proposed in this paper. For the regular circular patch antenna, using a foam layer of thickness ∼0.13λ0 as a supported substrate, an impedance bandwidth of 35% and a gain of over 8.0 dBi have been obtained. For the compact semicircular patch antenna, an impe...

Experimental results for an L-probe-fed shorted triangular patch antenna are presented. Using a foam layer of thickness ∼0.13λ0 as a supported substrate, an impedance bandwidth of 61% (SWR≤2) and a gain of over 4.0 dBi in the bandwidth have been obtained. The far-field patterns are stable across the passband. © 2001 John Wiley & Sons, Inc. Microwav...

Simulation and experimental results are presented for U-slot patch antennas with a shorting pin. The patch area is a fraction of the regular U-slot patch while the impedance bandwidth is over 10%

Experimental results for an L-probe-fed shorted semicircular patch antenna are presented. Using a foam layer thickness ∼0.12λ0 as a supported substrate, an impedance bandwidth of 57% (SWR≤2) and a gain of over 4.0 dBi in the majority of the wide bandwidth have been obtained. The far-field patterns are stable across the passband. © 2001 John Wiley &...

A broadband quarter-wavelength patch antenna with a U-slot is presented. Using a foam layer of thickness ∼0.07λ0 as a supported substrate, an impedance bandwidth of 27% (SWR≤2) has been obtained. The far-field patterns are stable across the passband. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 328–330, 2001.

In this paper, the finite-difference time-domain (FDTD) method is employed to analyze L-probe proximity-fed rectangular patch antennas. Numerical results for the input impedance, co- and cross-polarization radiation patterns are presented and compared with the measurements. Good agreement between the computed and measured results is obtained. The e...

Symmetrical and asymmetrical partially shorted patch antennas are numerically studied using the finite-difference time-domain method. It is observed that the patch size of the asymmetrical partially shorted case can be reduced more than that of the symmetrical case, while the bandwidth of the former is less than that of the latter. © 2001 John Wile...

Symmetrical and asymmetrical partially shorted patch antennas are numerically studied using the finite-difference time-domain method. It is observed that the patch size of the asymmetrical partially shorted case can be reduced more than that of the symmetrical case, while the bandwidth of the former is less than that of the latter. (C) 2001 John Wi...