Yoshihiro Notani

A 38/77 GHz MMIC transmitter chip set for automotive applications

This paper describes the successful development of 38/77 GHz transmit MMICs for automotive applications. They consist of a 38 GHz amplifier, a frequency doubler, and a 77 GHz power amplifier. These amplifiers achieve output powers of 16 dBm at 38 GHz and 15 dBm at 76.5 GHz at 1 dB gain compression point. The output power of the 77 GHz amplifier is one of the highest delivered by a single chip MMIC at 76.5 GHz. The frequency doubler delivers an output power of 5.7 dBm at 76.5 GHz. These results are promising for automotive applications in the W-band.

Millimeter-wave MMIC switches with pHEMT cells reduced parasitic inductance

High isolation millimeter-wave switches have been successfully developed using a newly developed line unified shunt pHEMT structure, which is effective to reduce parasitic inductance of its short circuit. The developed V-band SPDT switch shows an isolation of greater than 40 dB and an insertion loss of 1.8 dB at 60 GHz, and the W-band SP3T switch shows an isolation of greater than 35 dB and an insertion loss of 2.5 dB at 77 GHz. Input and output return losses are better than 12 dB in ON-state. These performances of high isolation and low insertion loss are the best among V-band and W-band pHEMT MMIC switches. The switches consume no DC power, and require no complex off-chip bias circuitry.

1 watt compact Ka-band MMIC power amplifiers using lumped element matching circuits

A compact MMIC chip set for Ka-band communication systems has been developed. A two stage power MMIC amplifier using only lumped elements and narrowly spaced lines for the matching circuit delivers 1.44 watt at 30 GHz with a very small die size of 1.94 mm/spl times/2.0 mm. The designing scheme is confirmed to be useful for cost reduction.

A W-band ultra low noise amplifier MMIC using GaAs pHEMT

This paper presents a newly developed 76 GHz three-stage LNA for automotive radar systems. The LNA utilizes multi band rejection filter type stabilizing circuits to achieve good noise figure together with good stability. The operating bias condition was carefully chosen to obtain low temperature dependence of gain. As a result, the LNA delivers a noise figure of 3.5 dB typically, small temperature dependence of gain of -0.016 dB/deg.C and high return loss using a highly conventional 0.19 /spl mu/m T-shaped gate AlGaAs/InGaAs/GaAs pHEMT process.

Study on slit pad structure to maintain MMIC characteristics both in on-wafer and on-package conditions in millimeter-wave applications

Slit pad structure has been suggested as a novel probing/bonding pad in order to achieve the same characteristics for MMIC between on-wafer and on-package cases in millimeter-wave applications. The dimensions for the new structure has been estimated with measurement for transmission lines and calculations using a commercial EM simulator (Sonnet EM), while a bonding strength for wire on the slit pad has been confirmed experimentally using wire pulling and pushing tests. As a result, it has become clear that a slit width of 5 /spl mu/m and a gap, which is a distance between a GND pad and a land pad, of 40 /spl mu/m are the most adequate dimensions to maintain MMIC characteristics both in on-wafer and on-package in broad frequency range. In addition, it has been demonstrated that the slit pad having the slit width of 5 /spl mu/m has maintained the same strength for wire bonding compared with wire bonding on a pad without the slit.