J.L. Masa

J.L. Masa
Universidad Autónoma de Madrid | UAM · Department of Electronical and Communication Technology

About

100
Publications
6,343
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561
Citations
Citations since 2016
34 Research Items
339 Citations
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20162017201820192020202120220204060
20162017201820192020202120220204060
20162017201820192020202120220204060
Introduction

Publications

Publications (100)
Article
Full-text available
This work presents the design and prototyping of a reconfigurable phased array in Ku band (16 to 18 GHz) implemented in waveguide technology. The design is based on the use of a novel seamless waveguide module integrating four reconfigurable phase shifters to adjust the relative phase shift between the unitary elements of a linear array, which are...
Article
A high-gain conical-beam traveling-wave array antenna based on a slotted circular waveguide is designed at the higher part of Ku -band. A single radiating element is formed by a ring of eight equally spaced slots fed by a circular waveguide. The excitation of the nonfundamental TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="h...
Article
A fully metallic radiating element is presented in this article for single and dual circular polarization applications. The shape of the radiating element corresponds to a bow-tie-shaped field rotator designed to generate two orthogonal modes in quadrature as a basis for circular polarization. The bow-tie-shaped basic element is able to provide low...
Article
Several low-cost feeding network configurations have been tested for an antenna array eligible for a 5G communication environment. Microstrip and substrate integrated waveguide (SIW) technologies have been evaluated in the feeding network and compared in terms of dielectric loss and directivity performance. Although microstrip dielectric loss is lo...
Conference Paper
A dual polarized travelling-wave array antenna in Ku-band is presented. The array design uses the two orthogonal modes TE10 and TE01 mode supported by a square waveguide feeding. Each single element of the array contains two orthogonal slots (transversal and longitudinal slots), forming a cross slot. Thus, transversal slots are excited by TE 10 mod...
Article
Full-text available
In this work, a planar UWB four elements antenna array with and without notch filter is designed. The feeding system of the array is an UWB four branch multiple segment power divider/combiner. Each branch has a three segments impedance transformer. Measurements show that the array works well within the band 3.1 to 10.6 with S11 lower than −10 dB. I...
Article
In this letter, additive manufacturing technologies have been evaluated for waveguide antenna array prototyping at Ku band. Direct Metal Laser Sintering and Stereolithography have been assessed in terms of manufacturing limitations, electrical performance, accuracy, cost and weight, compared to traditional manufacturing methods. This assessment is...
Article
The incoming 5G systems propose unprecedented communication capabilities that require a maximization of the channel and spectrum exploitation. Waveguide antenna arrays can play an important role in 5G environments due to their high performance in terms of efficiency and bandwidth. Moreover, higher frequencies appear necessary in order to achieve th...
Article
In this paper, a super-wideband (SWB) printed monopole antenna has been designed and manufactured. The measured frequency band in terms of reflection coefficient is from 3.1 to 20 GHz under a −10 dB criteria, thanks to the inclusion of a taper impedance adapter. This single antenna has been used to implement and analyze several MIMO antenna configu...
Article
A mechanical technique to provide beam steering capabilities to a linear array antenna is presented. The methodology is based on the insertion of metallic tuning screws into power dividers in rectangular waveguide technology. These tuning screws establish a short-circuit between the top and bottom plates of the waveguide, and a phase change in the...
Article
A mechanical technique to tune the radiating performance of a waveguide-fed slot is presented. Three metallic tuning screws are introduced through the bottom wall of the feeding waveguide. The field radiated by the slot is mechanically controlled with the insertion length of the tuning screws and a good input matching response is also maintained. O...
Article
In this article, a linearly polarized 4-element linear array in Ku band is presented. The single element consists of a circular microstrip patch capacitively coupled to a printed slot-end WR-51 waveguide. A corporate waveguide feeding network at H-plane is designed, which is composed of bends, T and Y-junctions. An optimization process with septums...
Article
A conformal array antenna with a reconfigurable radiation pattern in the azimuth plane at Ku band is presented. An eight-faced prism has been set as 3D antenna structure. The radiating element consists of a rectangular waveguide ended on a slotted-cavity. A radial waveguide network fed by a symmetrically placed coaxial probe has been implemented to...
Article
This article presents the design of a novel dual polarized waveguide fed circular microstrip patch antenna for Ku band applications. The circular microstrip patch is fed by using a square waveguide and a cross slot. The cross slot consists two orthogonal slots for coupling the energy associated with two orthogonal modes propagated in the square wav...
Article
A conformal array antenna has been designed in waveguide technology in order to obtain an omnidirectional radiation pattern in the azimuth plane at Ku-band. The antenna shape is a regular prism where the single radiating elements, which consist on a rectangular waveguide ended on a cavity-slot, are placed on the planar faces of the prism. The physi...
Conference Paper
This paper presents a design proposal for controlling the five thousand fiber positioners within the focal plate of the DESI instrument. Each of these positioners is a robot which allows positioning its optic fiber with a resolution within the range of few microns. The high number and density of these robots poses a challenge for handling the commu...
Article
Full-text available
In this paper, the design and fabrication of dual polarization microstrip patch antennas for ultra wideband applications with notch at 5-6 GHz is presented. The designed antenna rejects the WLAN signals and work properly in the entire remaining ultra-wideband. Two antennas are designed for two different frequency band of ultra wideband, and upon co...
Article
In this article, a linearly polarized 2 × 2 patch array uniformly fed by a corporate substrate integrated waveguide network for Ku band is presented. Undesired main beam steering is avoided by means of a fully corporate feeding network, although grating lobes may appear due to greater separation between radiating elements. Moreover, a reduced patch...
Article
A computer automated design methodology to synthesize a progressive wave array antenna is presented. The proposed method is based on the generalized-scattering matrix and spherical wave expansion analysis of the array. Mutual coupling effects between radiating elements are inherently considered in the design process. A linearly polarized 24-element...
Article
A conformal patch array antenna with omnidirectional pattern in the azimuth plane at Sband is presented. A theoretical study of the generated ripple in the omnidirectional radiation pattern according to the number of faces that conform the array has been computed. A six-faced regular prism 3D structure has been chosen following a maximum 3 dB rippl...
Conference Paper
Full-text available
Power division/combination is a very important function for achieving high-performance power amplification in microwave and millimeter-wave systems, allowing the use of simpler individual amplifiers to provide microwave/millimeter wave high power signals. In this paper we address the development of divider/combiners in waveguide technology for larg...
Article
This article presents the design and development of a waveguide fed microstrip patch antenna for Ku band applications. A circular patch is fed using a conventional WR-51 rectangular waveguide ended with a feeding slot capacitively coupled to the radiating patch. The design is optimized using the electromagnetic software CST Microwave Studio. The an...
Article
A novel method for considering radiating structures independently to their feeding networks is presented. The integration of both parts separately designed suffers a critical misalignment with the theoretical behaviour caused by the mutual coupling effects between adjacent elements. This method analyses radiated near E-field monitors to adjust the...
Article
This article presents a novel design of dual polarized microstrip patch antennas for ultra-wideband (UWB) applications. Two antennas are designed for different frequency band of UWB. Both antennas are loaded together and the combined antenna is designed for the entire UWB. The designed antenna is optimized using CST Microwave Studio simulator. The...
Article
Propagation loss models for indoor environment are presented. The narrowband directive channel propagation loss in indoor environment at three frequency bands namely (2.4, 3.3 and 5.5) GHz is measured. Sets of directive panel antennas are used in the measurements. RF signal generator and a spectrum analyzer are used in the measurement campaign. It...
Conference Paper
A Substrate Integrated Waveguide (SIW) has been used to feed a progressive wave linear array of 16 double stacked patches. The amplitude and phase performance has been achieved by means of coupling patches, which are placed inside the SIW. An antenna prototype has been manufactured with a multilayer PCB structure. 16 dBi and 80 % peak gain and effi...
Article
A linearly polarized patch array with direct probe feed over substrate integrated waveguide (SIW) network (LP-PASIW) for Ku-band is presented. A double-stacked microstrip patch structure has been used as radiating elements. Internal SIW coupling patches are placed inside the SIW to obtain the desired radiation pattern. The internal coupling and ext...
Article
Full-text available
A Substrate Integrated Waveguide (SIW) planar array is presented using a right handed circularly polarized (RHCP) element with four crossed tilted radiating slots. In addition, a pair of metallic tuning vias is included to really improve the re°ection of longest slots. A corporate feeding network over SIW has been designed for distributing the inpu...
Article
The insertion loss of different materials is measured at 2.4, 3.3 and 5.5 GHz bands. Directive antennas with a nominal gain of 19 dB are used in the measurement campaign. The height of the antennas has been selected to have the minimum possible re°ection from around surfaces. Thick concrete wall, thick concrete column and tree's insertion loss are...
Article
The insertion loss of different materials is measured at 2.4, 3.3 and 5.5 GHz bands. Directive antennas with a nominal gain of 19 dB are used in the measurement campaign. The height of the antennas has been selected to have the minimum possible reflection from around surfaces. Metallic door with porthole window, metallic grid, glass window, human b...
Article
The purpose of this study is to characterize the indoor channel for IEEE 802.16 (WiMAX) at 3.3–3.6 GHz frequency. This work presents a channel model based on measurements conducted in commonly found scenarios in buildings. These scenarios include closed corridor, wide corridor and semi open corridor. Path loss equations are determined using log-dis...
Conference Paper
A 16-element circularly polarized (CP) Substrate Integrated Waveguide (SIW) linear array antenna with -26 dB Taylor distribution and 2% residue power at 17 GHz is designed. The single element consists of four crossed inclined radiating slots. In this configuration, reflection goals on the linear array are not fully achieved. For this reason a tunin...
Article
In this work, the propagation loss of three short range directive channels at 5.5 GHz is measured using different directive antennas and a Vector Network Analyzer (VNA). Results are given for a channel bandwidth of 300 MHz which will be the future channel bandwidth of IEEE 802.11 ac system. It has been noted that the multipath induced fading tends...
Article
In this work, the propagation loss due to diffraction and insertion losses for indoor scenario at 5.6 GHz band are measured using directive antenna and a Vector Network Analyzer (VNA). It is shown that the insertion loss of a metallic door with porthole window varies from several dB due to the propagation loss via the porthole glass up to 50 dB due...
Article
A linearly polarized radial line patch antenna with internal coupling patches is presented. A non-resonant antenna structure has been designed, with a 0.68 λ<sub>0</sub> radial spacing between element rings. A uniform amplitude and phase feed scheme has been implemented. Therefore, a phase compensation microstrip structure (external to the radial w...
Conference Paper
A circularly polarized slot radiator in millimetre band is presented. Low reflection and good polarization performance is obtained in comparison with state of art slot elements. A high gain array prototype has been implemented in substrate integrated waveguides (SIW) technology, in order to check the new element performance. A cosecant amplitude co...
Article
A circularly polarized slot array antenna in millimetre band is presented. A cosecant amplitude coverage in the elevation plane, as well as a 6° tilted monopulse pattern in the azimuth plane, is obtained. The radiating slot array is implemented over substrate integrated waveguides (SIW). A microstrip feeding network with coaxial to SIW transitions...
Article
The purpose of this study is to characterize the indoor channel for IEEE 802.16 (WiMAX) at 3.5 GHz frequency band. This paper presents a channel model based on measurements conducted in commonly found scenarios in buildings. These scenarios include narrow corridor, wide corridor (a passage) and semi open corridor. Path loss equations are determined...
Article
In this work, results of an analytical analysis to assess the effect of Ultra Wide Band (UWB) emissions on the Worldwide Interoperability for Microwave Access system (WiMAX) are presented. The WiMAX range is evaluated with and without the UWB interference. Free space propagation model is used to calculate the UWB signal power that interferes with W...
Article
A cavity-backed bow-tie dipole antenna is presented as base station antenna for wide band American and European cellular communication systems (1.7–2.17 GHz). A beam widening of the horizontal plane is achieved by the cavity aperture reduction and the inclusion of a metallic support between the cavity floor and the antenna reflector plane. The stru...
Article
A 8×8 reconfigurable array antenna with dual lineal/circular polarization for WIMAX applications at 3.5 GHz has been designed. The antenna is composed of 4 elements basic cell sub-arrays with a Butler matrix inside. The basic cell sub-arrays are combined by means of digital phase shifters. The measured results of the radiating elements and RF modul...
Article
Nowadays, satellite communications are basic for the human lifestyle. In this way, a smart, conformal, and multiarray antenna (GEODA) is being developed in order to receive signals from several satellites simultaneously in the 1.7 GHz working band. An adaptive beam system is able to follow the signals from the satellite constellation. The complex s...
Article
A parallel plate waveguide antenna is presented with microstrip patches as radiating elements. Rectangular patches are also placed inside the waveguide as coupling field structures from the waveguide to the radiating elements. The connections from the coupling to the radiating patches are made by means of vias. The field propagated along the parall...
Article
A broadband circularly polarized patch antenna is presented in X band. The antenna operates simultaneously with left/right or right/left hand circular polarization in both reception (7.25–7.9 GHz) and transmission bands (7.9–8.4 GHz). A double coaxial probe feed has been implemented, as well as, a 90° branch-line coupler to obtain the desired circu...
Conference Paper
A low profile dual linear/circular polarization antenna is presented for 3.5 GHz WiMAX band (3.4 - 3.6 GHz ap 5.7 % bandwidth). An external polarizer composed of 45deg tilted strips on a printed circuit is placed significantly close over the radiating patches, and a circular polarization bandwidth widening is obtained. 8% average bandwidth has been...
Conference Paper
GEODA is a multiple planar array smart antenna that is being developed in order to receive and track several satellite signals simultaneously. GEODA antenna has an special structure that allows receiving signals from 5deg to broadside in elevation and 360deg for azimuth in the 1.7 GHz working band. Several arrays shape the antenna and work independ...
Article
A low profile double-layer polarizer structure is presented for planar patch antennas to obtain circular polarization in 3.5 GHz WiMAX band (3.4–3.6 GHz ≈ 5.7% bandwidth). Each polarizer layer is composed of 45 • tilted metallic strips on a printed circuit. A bandwidth widening is obtained due to a significant reduction of the distance between pola...
Article
A wide band antenna working simultaneously at GSM, UMTS and PCS band is presented. Radiation features of the main radiating element (dipole) are modelled by using a rectangular cavity with walls higher than the dipole height. Antenna performance is also improved by using a metallic square sheet placed above the dipole (reflection aspects) and a met...
Conference Paper
Full-text available
This is a brief of the development of a new multiple-array antenna, working on the 1.7 GHz band. The main purpose of the project is to establish communications between a satellite constellation and the terrestrial station. Signals from the constellation is followed by the antenna by means of an adaptive beam system.
Article
A planar antenna is presented as part of a Signal Identification System working at 1.06 GHz. The antenna presents a monopulse radiation pattern. Likewise, a scanning of the main beam direction is achieved in a ±45° azimuth coverage. A limited 3 dB amplitude drop of the received signal at the edges of the angular scanning area is only permitted. Fur...
Article
Full-text available
Nowadays, satellite communications are basic for the human lifestyle. In this way, a smart, conformal and multiarray antenna (GEODA) is being developed in order to receive signals from several satellites simultaneously in the1.7GHz working band. An adaptive beam system is able to follow the signals from the satellite constellation. The complex stru...
Conference Paper
The topic of this paper is the work carried out within work package 2.4-3 of the EU network "antenna centre of excellence" (ACE). This work package is concerned with structuring research on conformal antennas. In particular, the work is focused on the problems associated with full benchmarking of conformal antennas, on development of hybrid program...
Conference Paper
This paper shows the design of a conformal array antenna system for reception of Metop satellite, L band signal. The antenna system is made of a set of individual beam steering planar antennas combined in an adaptive receiver, to form a dome antenna. This combination allows optimum satellite reception and interference protection coming from other s...
Conference Paper
The design of an antenna for a Signal Identification System which works at 1.06GHz with a bandwidth of 80 MHz is presented. The maximum gain value of the total antenna required is 16.6 dBi. Moreover, a plusmn50deg sweep of the aiming angle signal with a 3 dB level loss in the edges is desired. The structure is based on a multi-layer configuration w...
Conference Paper
This paper shows the development of a new multiple-array antenna, working on the 1.7 GHz band. The main purpose of the project is to establish communications between a satellite constellation and the terrestrial station. It consists of some triangular phased arrays of double circular patches, controlled by an electronic subsystem in order to obtain...
Conference Paper
In this paper a broad band circularly polarized antenna for satellite communications in X band is presented. It is composed of patch antennas, in order to satisfy the necessity of getting a portable antenna. Additionally it is required to get a bandwidth of 14% with a reflection of 15 dB and an isolation of 17 dB, so a double stacked patch configur...
Conference Paper
The work carried out within Work Package 2.4-3 of the EU network "antenna centre of excellence" (ACE) is presented in this paper. This work package is concerned with structuring research on conformal antennas. In more details, the work is focused on the problems associated with full benchmarking of conformal antennas, on development of hybrid progr...
Conference Paper
In this paper the design of an antenna for a signal identification system which works at 1.06GHz is presented. The system requires reduced dimensions because this antenna must be placed on an airplane. The structure is based on a multi-layer configuration with double stacked patch fed by a coaxial probe. Low-cost material has been used.
Conference Paper
A conformal antenna is defined as an antenna that conforms to a surface whose shape is mainly determined by considerations other than electromagnetic, e.g. aerodynamic or hydrodynamic considerations. This definition should be extended to antennas whose shape is not planar and whose shape is determined with specific electromagnetic reasons like cove...
Article
A circularly polarized omnidirectional millimeter wave monopole with parasitic strip elements for a system of arrival signal direction detection in millimeter band is presented. As a consequence of the radiation pattern requirements, the proposed antenna consists of a conical skirt monopole with a polarizer radome. The polarizer converts a wave fro...
Article
A circularly polarized slotted array antenna is presented. The array is fed by a circular waveguide propagating the TM01, to properly generate the required polarization. An omnidirectional azimuth radiation pattern is obtained, as well as a −10°/+30° elevation antenna coverage. Low losses are achieved because of the waveguide feed. The slot array i...
Conference Paper
An antenna for a Signal Identification System has been designed. The objective of this design is to detect the angle of the arrival signal by electronic sweeping and a monopulse system in the horizontal plane. The antenna frequency performance is fixed at 1.06 GHz with an 80 MHz bandwidth (7.54 %). A ±60° sweeping of the aiming angle signal with...
Article
A new feeding structure based on parallel plates radial line applied on planar arrays is shown in this paper. When a high gain antenna for a high frequency system is being designed, low losses feeding networks must be taken into account [1]. Typically waveguide feeding networks are being used in this kind of applications. In order to show how paral...
Conference Paper
In this paper, the monopulse behavior in planar antennas with parallel plate feeding has been studied and applied in two different designs. Knowing the field structure in the parallel plate waveguide for different inputs number is important for an appropriate dimensioning of the coupling elements (microstrip coupling lines) that depends on the desi...
Conference Paper
This paper presents a circularly polarized patch array in 37 GHz frequency, integrated in a narrow band application (BW < 1%) for signal detection. The designed array has to fulfill some specific requirements related to its radiation pattern (monopulse in the horizontal pattern and cosecant shape in the vertical one); other significant requirements...
Conference Paper
Full-text available
A radial line patch antenna (RLPA) with external feeding phase control is presented. The coupling mechanism from the radial waveguide to the patches is achieved by inner small microstrip lines. The fed amplitude is controlled by the dimensions of these lines, whereas the phase is modified by outer transmission lines. The coupling internal lines are...
Article
Radial-line antennas are an excellent choice for a high-gain and efficient design, as they present an easy manufacturing process due to their planar structure. In this paper, a new feeding mechanism, from the transmitting radial waveguide to the radiating elements, is proposed. This coupling structure is based on microstrip lines placed inside the...
Conference Paper
Full-text available
We present a circularly polarized patch array in 37 GHz frequency, within a narrowband application (less than 1%) for signal detection. The designed array needs to have some specific requirements related to its radiation pattern (monopulse configuration to identify the input direction of a signal), circular polarization (RHCP) with an axial ratio u...
Conference Paper
Full-text available
A radial line planar antenna with external feeding phase control is presented. The coupling mechanism from the radial waveguide to the patches is achieved by inner small microstrip lines. The fed amplitude is controlled by the dimensions of these lines, whereas the phase is modified by outer transmission lines. The coupling internal lines are also...
Conference Paper
Full-text available
In this paper a new parallel plate antenna is presented. The antenna operates in the DBS band. As a difference to traditional designs a TE<sub>NO</sub> has been created inside the parallel plate waveguide. The field propagating inside is coupled through microstrip lines to the radiating patches. A 15deg tilted radiation pattern is desired. A protot...
Article
This paper presents the design and construction of a millimetre wave antenna to be used in a monopulse radar system [1]. The antenna must presents a narrow pencil beam with a monopulse double beam in both principal planes. Design conditions are restricted to low cost fabrication. Printed slots over mechanized waveguide have been selected as radiati...
Article
Full-text available
Coupling is an important aspect to be considered in the design process of antenna arrays. The real feeding radiated coefficients can be quite different from the theoretical ones because of this effect. In this paper, a characterization and compensation model is presented. This procedure is capable of matching each element of the array. All the para...
Article
In the design process of array antennas, coupling is one of the most important elements to be considered. The real feeding-radiated coefficients can be quite different from the theoretical ones because of this effect. In this paper, a characterization method is presented that allows each element to be matched from the array. All the parameters of t...
Conference Paper
Full-text available
Adaptive type smart antennas have not been implemented yet on the deployed UMTS systems, although UTRA-UMTS preview their operation and they also could improve capacity especially in a multiservice environment. This paper describes a set of novel measurement techniques that must be performed to evaluate the correct operation of a smart antenna syst...
Conference Paper
Full-text available
Adaptive type smart antennas have not been implemented yet on the deployed UMTS systems, although UTRA-UMTS preview their operation and they also could improve capacity especially in a multiservice environment. This paper describes a set of novel measurement techniques that must be performed to evaluate the correct operation of a smart antenna syst...
Conference Paper
Full-text available
INTRODUCCION Slot waveguide antennas have been widely studied in state of art [1] due to their excellent low losses characteristics. On the contrary these antennas have a resonant behaviour, therefore they can not be useful for wideband applications. In this paper we present an array of slot waveguide elements in 37 GHz frequency, with a narrowband...
Conference Paper
A new radial line planar antenna is proposed. We incorporate a new feeding concept into the radial waveguide which allows the designer a better control of the amplitude and phase configuration of the structure and polarization of radiated field. Some simulation results are presented with a real antenna.
Conference Paper
Full-text available
In the design process of array antennas, coupling is one of the most important aspects to be considered to complete a realistic model. The real feeding radiated coefficients can be quite different from the theoretical ones because of this effect. A characterization and compensation model is presented. This procedure is able to match each element fr...
Conference Paper
Full-text available
Adaptive type smart antennas have not been implemented yet on the deployed UMTS systems, although UTRA-UMTS preview their operation and they also could improve capacity especially in a multiservice environment. This paper describes a set of novel measurement techniques that must be performed to evaluate the correct operation of a smart antenna syst...
Conference Paper
Adaptive type smart antennas have not been implemented yet on the deployed UMTS systems, although UTRA-UMTS preview their operation and they also could improve capacity especially in a multiservice environment. This paper describes a set of novel measurement techniques that must be performed to evaluate the correct operation of a smart antenna syst...