*Article* **A 66–76 GHz Wide Dynamic Range GaAs Transceiver for Channel Emulator Application**

**Peigen Zhou \*, Chen Wang, Jin Sun, Zhe Chen , Jixin Chen and Wei Hong**

State Key Laboratory of Millimeter Waves, School of Information Science and Engineering, Southeast University, Nanjing 210096, China; chenwang@seu.edu.cn (C.W.); 220200844@seu.edu.cn (J.S.); zhechen@seu.edu.cn (Z.C.); jxchen@seu.edu.cn (J.C.); weihong@seu.edu.cn (W.H.) **\*** Correspondence: pgzhouseu@seu.edu.cn

**Abstract:** In this study, we developed a single-channel channel emulator module with an operating frequency covering 66–67 GHz, including a 66–76 GHz wide dynamic range monolithic integrated circuit designed based on 0.1 μm pHEMT GaAs process, a printed circuit board (PCB) power supply bias network, and low-loss ridge microstrip line to WR12 (60–90 GHz) waveguide transition structure. Benefiting from the on-chip multistage band-pass filter integrated at the local oscillator (LO) and radio frequency (RF) ends, the module's spurious components at the RF port were greatly suppressed, making the module's output power dynamic range over 50 dB. Due to the frequency-selective filter integrated in the LO chain, each clutter suppression in the LO chain exceeds 40 dBc. Up and down conversion loss of the module is better than 14 dB over the 66–67 GHz band, the measured IF input P1 dB is better than 10 dBm, and the module consumes 129 mA from a 5 V low dropout supply. A low-loss ridged waveguide ladder transition was designed (less than 0.4 dB) so that the output interface of the module is a WR12 waveguide interface, which is convenient for direct connection with an instrument with E-band (60–90 GHz) waveguide interface.

**Keywords:** channel emulator; E-band; GaAs; ridged waveguide ladder transition; wide dynamic range
