Publications (18)9.76 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: For the realization of a high-efficiency antenna for 60 GHz-band wireless personal area network, we propose placing a CMOS RF circuit and an antenna on opposing sides of a silicon chip. They are connected with low loss by a coaxial-line structure using a hole opening in the chip. Since the CMOS circuit is driven differentially, a differential-feed antenna is used. In this paper, we design and measure a differential-feed square patch antenna on a silicon chip. To enhance the radiation efficiency, it is placed on a 200 μmthick resin layer. The calculated radiation efficiency of 79% includes the connection loss. A prototype antenna is measured in a reverberation chamber, and its radiation efficiency is estimated to be about 81 ± 3%. Copyright © 2016 The Institute of Electronics, Information and Communication Engineers.
- [Show abstract] [Hide abstract] ABSTRACT: We have proposed to place an RF circuit and an antenna on each side of a silicon chip in the 60 GHz band, respectively, and to connect between them with low loss by a coaxial-line structure using a hole opening in the chip. In this paper, we fabricate a 2×2 circularly polarized patch array in an area of 5 mm square on a silicon chip and have coaxial-line connection with a separated quadrature oscillator chip sized by 1 mm square. Then we measure characteristics of the antenna chip.
- [Show abstract] [Hide abstract] ABSTRACT: As a first step towards the realization of high-efficiency on-chip antennas for 60 GHz-band wireless personal area networks, this paper proposes the fabrication of a patch antenna placed on a 200 μm thick dielectric resin and fed through a hole in a silicon chip. Despite the large tan δ of the adopted material (0.015 at 50 GHz), the thick resin reduces the conductor loss at the radiating element and a radiation efficiency of 78%, which includes the connecting loss from the bottom is predicted by simulation. This calculated value is verified in the millimeter-wave band by experiments in a reverberation chamber. Six stirrers are installed, one on each wall in the chamber, to create a statistical Rayleigh environment. The manufactured prototype antenna with a test jig demonstrates the radiation efficiency of 75% in the reverberation chamber. This agrees well with the simulated value of 76%, while the statistical measurement uncertainty of our handmade reverberation chamber is calculated as ±0.14 dB. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.
- [Show abstract] [Hide abstract] ABSTRACT: This paper describes cryogenic 36-45 GHz InP low-noise amplifier monolithic microwave integrated circuits (MMIC's) with an improved noise temperature by eliminating parasitic parallel-plate resonance modes. These MMIC's are used for a Radio Astronomical receiver, which needs the ultimate super low-noise and wide-band frequency characteristics, such as those in ALMA Band 1. The MMIC chips were designed in the coplanar waveguide (CPW), and mounted to the AlN substrate with a flip-chip assembly, which was promising compared to wire bonding. The flip-chip assemblies, however, are prone to cause the parasitic parallel plate resonance mode (PPM). The relationship between the S-parameters and the PPM was investigated by using a 3D-electromagnetic simulation of the simple transmission-line test-chip with the same chip size as that of the actual MMIC. In order to eliminate the PPM, additional bumps were mounted on the simple transmission-line test-chip, and the effect of these bumps was confirmed by the simulation. These results obtained from the simple transmission-line test-chip were applied to an actual MMIC chip assembly. The MMIC assembled with the additional bumps had no abnormality in the measured S-parameters, and the PPM had been eliminated up to 65 GHz. Moreover, the stability factor, K, became more than 2.4 over 36-45 GHz. This InP low-noise amplifier MMIC exhibited a gain of 15 dB and a noise temperature of 180-240 K at room temperature in the frequency range of 36-45 GHz. When cooled to 28 K, a gain of 17 dB and a noise temperature of 22-35 K were obtained at a power consumption of 4.7 mW over 36-45 GHz. A high-gain amplifier module consisting of two cascaded chips, exhibited a gain of 27-30 dB and a noise temperature of 25-30 K at the ambient temperature of 22 K in the frequency range of 41-45 GHz.
- [Show abstract] [Hide abstract] ABSTRACT: A small package suitable for the mobile terminals of the 60-GHz wireless personal area network is proposed. Two antennas for Tx and Rx are integrated in the package. The antenna provides the end-fire radiation from the side face of the substrate. The package is mounted on the edge of a printed circuit board by using the ball grid array assembly. The antenna is composed of a post-wall waveguide and a slab waveguide with metal sidewalls. The gain and beamwidth are determined by the size of the slab waveguide. The sidewalls are for the design of the beamwidth in the $H$-plane and for realizing the high isolation between Tx and Rx antennas. The beamwidths of the fabricated antenna were measured to be 47° and 46° in the $E$- and $H$-plane at 60 GHz, respectively. The gain more than 7.8 dBi was measured in the frequency range from 59 to 66 GHz. The package was fabricated for the evaluation of the isolation. The measured average isolation level between Tx and Rx antenna was 46.0 dB in the frequency range above. The antenna characteristics and isolation level are sufficient for the 60-GHz WPAN system.
- [Show abstract] [Hide abstract] ABSTRACT: A small antenna with high isolation characteristics is designed and evaluated. Since the antenna provides lateral radiation, the antenna is suitable for the wireless file-transfer system, and it can be integrated into surface-mount package. The characteristics of the fabricated antenna meet the required gain of 6 dBi and beamwidth of 40–60 degrees. The size of the antenna is 7.5 mm × 8.4 mm × 1.0 mm, and is 14 % smaller than conventional one. The designed Tx/Rx antenna isolation characteristics is greater than 50 dB, which has the margin of 20 dB to required isolation.
- [Show abstract] [Hide abstract] ABSTRACT: This paper proposes a cost-effective antenna package suitable for the mobile terminal of the wireless file-transfer system. The antenna package provides the end-fire radiation from the open-ended post-wall waveguide built into the side of the package. The antenna package, in which a 60-GHz CMOS chip is attached, is mounted on the edge of a printed circuit board by the ball-grid-array assembly. The fabricated antenna, to be built in the package, had the size of 4.8 mm × 6.4 mm × 1.0 mm. The beamwidths of 120° (E-plane) and 72° (H-plane) and the gain of 2.2 dBi were measured at 60 GHz. The cost-effective antenna package with two antennas for the transmitter (Tx) and the receiver (Rx) was fabricated. The isolation between the Tx and Rx antenna was measured to be greater than 36 dB in the frequency range of 59-66 GHz. Moreover, the antenna with higher gain required from the system was fabricated. The gain of 6 dBi in the range of 58-68 GHz was measured. The beamwidth of 60° (E-plane) and 30° (H-plane) at 60 GHz were measured, respectively.
- [Show abstract] [Hide abstract] ABSTRACT: A de-embedding method using an electromagnetic (EM) simulator is proposed to extract field-effect transistor (FET) characteristics from FET test-pattern measurements. In the proposed method, the S-parameters of the parasitic circuit are analyzed using the EM simulator. Hybrid S/Z-parameters, converted from S-parameters, are used for the parasitic circuit to express waveguide ports with S-parameters and lumped-element ports with Z-parameters. The proposed method requires a high accuracy of the EM simulator; this method was verified by comparing calculated and measured frequency characteristics of the S-parameters of an open/short-pattern. It was shown numerically that the proposed de-embedding method has a better accuracy than the conventional method, which uses the open/short-pattern. For example, the extraction error is below 5% up to 75 GHz for the proposed method and a 5% error is exceeded around 30 GHz for the conventional method. The dominant error factor in the conventional de-embedding method using the open/short-pattern was investigated. It was established that the approximation of the parasitic circuit by an equivalent circuit topology is the cause of the error. The extraction of the FET characteristics by measured data is demonstrated and it is shown that the proposed method can be applied to extract active devices.
- [Show abstract] [Hide abstract] ABSTRACT: A cost-effective surface-mount antenna-package suitable for the mobile terminal of the wireless file-transfer system was fabricated. The package has two post-wall waveguide aperture antennas with the end-fire radiation. The package has the size of 14.4 mm × 14.4 mm × 1.0 mm. The isolation between Tx and Rx antenna was measured to be less than -36.2 dB in the frequency range of 59 - 66 GHz. The measured |S21| from the GSG pad on the package to one on the printed circuit board (PCB) were -0.23 dB for IF of 2-GHz and -1.5 dB for external 20-GHz local signal. The measured |S11| were less than -10 dB for both IF and 20-GHz. The repeatability of the ball grid array (BGA) assembly was also confirmed by the small measurement variation.
- [Show abstract] [Hide abstract] ABSTRACT: The lateral radiation millimeter-wave antenna using post-wall waveguide was proposed and the two type of prototype antenna was estimated. As a result, the measured directivity and gain of prototype antenna agree with the simulated data using simply-modeled HFSS reasonably. It was confirmed that the proposed antenna characteristics was able to estimate by simple model simulation. And the feasibility of the antenna package was also demonstrated by the measurement of a prototype.
- [Show abstract] [Hide abstract] ABSTRACT: Transitions between a post-wall waveguide and a microstrip line are proposed as the key components for cost-effective millimeter-wave modules. A transition with a coaxial structure is investigated for LTCC laminated layers and 11.3% bandwidth for the reflection smaller than −15 dB is realized in 60 GHz band. The overall connector loss with 1 cm post-wall would be about 0.8 dB. The degradation due to fabrication error is also assessed. The transition in LTCC substrate fulfills electrical and manufacturing demands in millimeter-wave bands.
- [Show abstract] [Hide abstract] ABSTRACT: Interfaces between a coaxial structure and a post-wall waveguide are proposed as the essential components for cost-effective millimeter-wave modules. PTFE substrate is selected in terms of loss and manufacturability. The reflection and the transmission characteristics are investigated. The short-stepped and the short-taper-stepped feeding structures provide 14.7% and 13.2% bandwidths for the reflection smaller than -15dB, respectively. The 46 x 40 mm(2) size antenna fed by the short-stepped structure in PTFE substrate gives 27.3 dBi with 58.2% efficiency at 60.0GHz. Feeding structures in PTFE substrate fulfill electrical and manufacturing demands in millimeter-wave bands.
- [Show abstract] [Hide abstract] ABSTRACT: Cost-effective 60 GHz modules were developed for home-link systems which needed the bit rate of several Gbps. The modules are composed of a packaged MMIC mounted on the printed circuit board and a post-wall planar antenna formed on the backside of the board. The antenna gain is 20 dBi. The board with the size of 75 Ã 32 Ã 1.2 mm3 is inserted into the card-edge connector to feed the IF signal and the DC power. The module can be characterized to have no mm-wave terminals. When the output power of the transmitter module ( Tx ) was 8 dBm at 61.0 GHz, the IF output power of the receiver module ( Rx ) PIFout was Â¿37 dBm at the distance D = 10 m between Tx and Rx. This experiment suggests the capability of the transmission with the bandwidth of 2.5 GHz and the C/N of 25 dB in the home-link systems.
- [Show abstract] [Hide abstract] ABSTRACT: A cost-effective receiver-module with built-in patch antenna was completed as well as a transmitter. Both the transmitter and the receiver have the local-oscillator in each package and have no terminal for the mm-wave signal. The linear-gain and the noise-figure of the receiver without the antenna were 35 dB and 5.5 dB, respectively. The measured phase-noise of the receiver were Â¿ 60 dBc/Hz at 1kHz, Â¿78 dBc/Hz at 10kHz, and Â¿88.5 dBc/Hz at 100 kHz off-carrier frequency. The average in the local-oscillation frequency variation on the temperature was 0.2 ppm/ C Â° The transmission system using the transmitter and the receiver with 23 dBi horn antenna exhibited the error-free high-speed data transmission per-formance within 9 m in the indoor QPSK 100 Mbps wireless LAN.
- [Show abstract] [Hide abstract] ABSTRACT: A new cost-effective RF-module with built-in patch antenna was proposed and developed for the drastic reduction in the cost of millimeter-wave wireless communication systems. The developed RF-module, which was hermetically sealed, exhibited the BER of less than 10Â¿6 at 156 Mbps and 59.5 GHz within the radius of 5 m in the indoor 8-PSK wireless data transmission experiment.
- [Show abstract] [Hide abstract] ABSTRACT: Abstract – A novel self-heterodyne scheme was proposed, which transmitted both the RF1 and an additional carrier RF2 produced by an additional single-tone IF2. The feature of this scheme is that the frequency-fluctuation and the phase-noise generated in the local-oscillator of the transmitter can be eliminated, because the RF1 and the RF2 have both the frequency-fluctuation and the phase-noise in phase. It was reported that cost-effective 60-GHz modules with this scheme applied exhibited the phase-noise of -110 dBc/Hz at 100 kHz off-carrier frequency.
Tokyo Institute of Technology
Edo, Tokyo, Japan
- Electrical and Electronic Engineering Department