X-band MMICs for a Low-Cost Radar Transmit/Receive Module in 250 nm GaN HEMT Technology

Abstract

This paper describes Monolithic Microwave Integrated Circuits (MMICs) for an X-band radar transceiver front-end implemented in 0.25 μm GaN High Electron Mobility Transistor (HEMT) technology. Two versions of single pole double throw (SPDT) T/R switches are introduced to realize a fully GaN-based transmit/receive module (TRM), each of which achieves an insertion loss of 1.21 dB and 0.66 dB at 9 GHz, IP1dB higher than 46.3 dBm and 44.7 dBm, respectively. Therefore, it can substitute a lossy circulator and limiter used for a conventional GaAs receiver. A driving amplifier (DA), a high-power amplifier (HPA), and a robust low-noise amplifier (LNA) are also designed and verified for a low-cost X-band transmit-receive module (TRM). For the transmitting path, the implemented DA achieves a saturated output power (Psat) of 38.0 dBm and output 1-dB compression (OP1dB) of 25.84 dBm. The HPA reaches a Psat of 43.0 dBm and power-added efficiency (PAE) of 35.6%. For the receiving path, the fabricated LNA measures a small-signal gain of 34.9 dB and a noise figure of 2.56 dB, and it can endure higher than 38 dBm input power in the measurement. The presented GaN MMICs can be useful in implementing a cost-effective TRM for Active Electronically Scanned Array (AESA) radar systems at X-band.

A Dual Load-Modulated Doherty Power Amplifier Design Method for Improving Power Back-Off Efficiency

“…This inevitably requires the power amplifier (PA) to work in the output power back-off (OBO) region, and the traditional PA architecture usually exhibits low efficiency in the OBO region. This will lead directly to a serious reduction in the efficiency of the entire transmitter [ 6 , 7 , 8 , 9 , 10 , 11 ]. As a PA architecture with high OBO efficiency, the Doherty power amplifier (DPA) [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ] has attracted the attention of a large number of researchers due to its simple circuit structure and easy broadband design.…”

Stability, Mounting, and Measurement Considerations for High-Power GaN MMIC Amplifiers

“…In [26][27][28], some techniques for the design of MMIC networks were developed which using different procedures to adapt impedances in monolithic circuits of all types. However, from our point of view, in most cases, these techniques are useful only for the specific problem explored in the articles in which they were presented and are difficult to apply to the design of MMIC networks in a systemic way.…”