High-power protection switch utilizing a new stub/line selectable configuration is presented. By employing the proposed circuit topology, the insertion loss at receiving mode and the power handling capability at transmitting mode can be independently designed. Therefore, the proposed circuit is able to achieve low insertion loss at receiving mode while keeping high-power performance at transmitting mode. To verify this methodology, MMIC switch has been fabricated in Ka-band. The circuit has achieved the insertion loss of 2 dB, the isolation of 25 dB, and the power handling capability of 40 dBm at 5% bandwidth.

This letter describes a high power monolithic GaAs FET transmit-receive switch (TR switch) with two FETs. Both FETs operate in the same states, low impedance state in transmitting and high in receiving, so rf voltage imposed on FET is low both in transmitting and receiving. The developed TR switch can handle more than 12 W peak power at X-band frequencies.

A new monolithic transmit-receive GaAs FET switch has been developed, named the FET series-shunt connected TR switch and capable of switching high rf transmitting power. Both insertion loss and isolation limitations of this type TR switch have been analyzed using the switching cutoff frequency of the control FET, and the formula for calculating the rated power is provided. A unique feature of this switch is that the power handling of the switch is not limited by the FET gate break-down voltage but is limited by the saturation current, so higher handling power capability is available by using FETs with a larger gate periphery. A design example of the TR switch at a rated power of 8 W in the transmit mode as well as the results of an X band switch are presented.

Miniaturized opto and microwave receiver module using DCCPWs (Double Conductor Coplanar Waveguides) have been developed for active phased array antennas. The module comprised by a microstrip-to-slot transition, two chips of low-noise MMIC amplifiers, and a laser diode module is fabricated on an ultra-thin package with 10301.5 mm3 in size and 2 g in weight to achieve an ultra-thin structure of active phased array antenna panels. The ultra-thin structure is attributed to the design of low-noise MMIC amplifiers using DCCPWs and laser diode modules using silicon V-groove technology and fiber alignment method.

A refection type and loaded-line type phase shifter switching multi phase-states has been described. This novel phase shifter circuit is constructed by adding switching FETs to a conventional 2-phase-state phase shifter. A conventional 3 bit phase shifter can be replaced by this type of phase shifter. The total chip size is reduced to 2/3. This paper reports on the design, fabrication, and performance of the novel reflection-type and loaded-line-type phase shifter MMICs.

Millimeter-wave monolithic low noise amplifier modules using 0.15 µm AlGaAs/InGaAs/GaAs pseudomorphic HEMTs have been developed at V- and W-bands for the Advanced Microwave Scanning Radiometer. To achieve low noise and high gain of V-band single-stage and W-band two-stage monolithic amplifiers, a reactive matching method is employed in the design of input noise matching and output gain matching circuits based on the results of on-carrier S-parameter measurements up to 50 GHz and noise parameter measurements at 60 and 90 GHz. A V-band four-stage monolithic amplifier module has been mounted on a hermetically-sealed package with microstrip interface and has achieved a noise figure of 3 dB with a gain of 42.2 dB at 51 GHz. A W-band six-stage amplifier module has been mounted on a hermetically-sealed package with waveguide interface and has achieved a noise figure of 4.3 dB with a gain of 28.1 dB at 91 GHz. These results represent the best noise figure performance ever achieved by multi-stage monolithic low-noise amplifier modules.