Toshihiro Shimura

76 GHz flip-chip MMICs for automotive radars

Using the flip-chip bonding technique, we developed a 76-GHz MMIC chip set for automotive radars. A chip set consists of a 76-GHz amplifier, a 76-GHz mixer, 76-GHz SPDT switches, a 38/76-GHz doubler, a 38-GHz voltage-controlled oscillator and a 38-GHz buffer amplifier.

A novel electromagnetic bandgap metal plate for parallel plate mode suppression in shielded structures

A novel type of metal plate structure incorporated with electromagnetic bandgap holes for use as metal shields with the capability of suppressing the propagation of unwanted parallel plate mode has been proposed. The holes can be of any shape and the periods of those holes should be selected to half the guided wavelength of the parallel plate mode at a desired center frequency of suppression. To show the validity of the proposal, inert electromagnetic wave simulation, results of a shielded microstrip structure designed for application in the 76 GHz frequency band are demonstrated. Experiments are performed with a prototype designed in the 10 GHz frequency band and parallel plate mode suppression is verified successfully with the excellent agreement between experimental and simulation results.

76 GHz Flip-chip MMICs in Through-hole Packages

We have developed novel hermetically sealed package with through-hole for the use in low-cost millimeter-wave applications. The package is available with specifications ranging from DC to 85 GHz. The insertion loss at feed-through of the package is less than 0.5 dB at 76 GHz. It is especially suitable for flip-chip MMICs. We have also developed 76 GHz flip-chip MMICs for automotive radar applications. A combination of flip-chip bonding technique and new package will provide a low cost millimeter-wave module. The MMIC modules have the following characteristics: The 76 GHz 4-stage amplifier has a gain of 22 dB. The frequency mixer with 1-stage amplifiers has a conversion loss of 2 dB. The 38/76 GHz frequency doublers with the 38 GHz 1-stage amplifier provide an output power of 0 dBm. The voltage-controlled oscillator provides an output power of 6 dBm. The 76 GHz SPDT switch has an insertion loss of 6 dB and an isolation of 15 dB.

60-GHz MMIC image-rejection downconverter using InGaP/InGaAs HEMT

We have designed, fabricated, and evaluated an InGaP/InGaAs/GaAs HEMT 60-GHz monolithic image-rejection downconverter. The downconverter consists of a four-stage low-noise amplifier and a single-balanced image-rejection active-drain mixer. The HEMTs used in the downconverter have gates of 0.1 /spl mu/m long and 100 /spl mu/m wide. The downconverter has a maximum conversion gain of 22.9 dB at 61 GHz and a minimum noise figure of 3.16 dB at 58.5 GHz with 5 dBm LO power input and 140 MHz IF output. These characteristics are, to our knowledge, the best report of an MMIC downconverter using an image-rejection active-drain mixer in this frequency range. This is a significant improvement from our previous report results in terms of the noise figure and conversion gain.

A compact PA MMIC module for K-band high-speed wireless systems

A K-band high-power MMIC amplifier module in a low-cost metal-ceramic package has been developed to provide an easy insertion of PA MMICs into K-band high-speed wireless systems. This PA module is comprised of a driver amplifier MMIC and a power amplifier MMIC with a total gain of 30 dB and a P/sub 1 dB/ of 33.5 dBm at frequencies between 23 and 26 GHz. The total performance of this module, G(dB)/spl times//spl Delta/f/f/sub 0/ is two times higher than previously reported works.

High isolation V-band SPDT switch MMIC for high power use [HEMTs application]

This paper presents design and performance of a V-band SPDT switch MMIC for high power use. The switch design utilizes distributed 5-shunt diodes. The developed SPDT switch shows an isolation of greater than 32 dB and an insertion loss of less than 1.8 dB in a broadband frequency range from 50 GHz to 70 GHz. Input and output return losses are better than 9 dB in ON-state. The chip size is 2.65 mm /spl times/1.33 mm. The power-handling capability was confirmed to be higher than 10 dBm of input power at 60 GHz. To our knowledge, this total broadband performance of high isolation and low insertion loss, as well as the high power-handling capability is the best among V-band SPDT switch MMICs so far.

HEMT-based MMIC single-balanced mixers for 60-GHz indoor communication systems

The authors developed V-band monolithic active-gate and active-drain mixers with a single-balance configuration. The HEMTs in both active mixers have an AlGaAs/GaAs structure and gates 0.15 /spl mu/m long and 100 /spl mu/m wide. The single-balanced active-gate mixer has a maximum conversion gain of -4.3 dB and only 2.5 dBm LO drive at 60-GHz. The gate mixer has a noise figure of 5.3 dB at 58 GHz and 0 dBm LO drive power. The single-balanced active-drain mixer has a maximum conversion gain of -6 dB and 13.5 dBm LO drive at 60 GHz. The drain mixer has a noise figure of 6.8 dB at 58 GHz and 8.5 dBm LO drive. The RF performances of active-gate and active-drain mixers fabricated on the same wafer are compared.<<ETX>>

A Single-chip Transceiver Module for 76-GHz Automotive Radar Sensors

We used novel flip-chip MMIC design techniques to develop a single-chip transceiver MMIC module for 76-GHz automotive radar sensors. The area of the MMIC chip is only 8.46 mm2. The MMIC is hermetically sealed in a module package, which is designed to allow direct-probe RF testing of the module.

Millimeter-wave beam multiplexing method using hybrid beamforming

A millimeter-wave beam multiplexing method using a hybrid beamforming is proposed. We theoretically show that inter-subarray coding at the subarray type interleaved configuration can reduce interference and multiple beams of the same high gain as the full connection type. The condition that a hybrid beamforming of the subarray type can create the multiple high gain beams is clarified. For the case of beam multiplexing, the interleaved configuration with inter-subarray coding is confirmed to be robust for interference increasing by errors of beam direction estimation. Therefore, we think that the interleaved configuration is suitable for millimeter-wave beam multiplexing.

Subfemtojoule 0.15 /spl mu/m InGaP/InGaAs/GaAs pseudomorphic HEMT DCFL circuits under 1 V supply voltage

We have fabricated side-wall assisted 0.15 /spl mu/m T-shaped gate pseudomorphic HEMT DCFL circuits with InGaP donor layers and obtained 22.3 ps basic delay and 0.8 fJ power-delay products at a supply voltage Vdd of 0.6 V with the driver gate width of 2 /spl mu/m. A master-slave type divide-by-two frequency divider which consists of eight 2-input NAND gates using a dual gate electrode structure shows stable operation of 10 GHz toggle frequency with a power consumption of 4.5 mW at Vdd of 0.8 V.