Integrated Compact Broad Ka-band Sub-ha- Rmonic Single Sideband Up-converter Mmic

Design, simulation and measurement results of the integrated compact up-converter MMICs (microwave monolithic integrated circuits) are presented and discussed. The design is performed to achieve low cost and high performance transmitter system for the Ka-band frequency applications. It is designed using antiparallel diode pair sub-harmonic single sideband mixer and three stage RF (radio frequency) amplifier. Microstrip lines and lumped elements are used together to achieve a compact chip size. The layouts of the circuits are designed with careful EM (electromagnetic) simulations to avoid inter-component couplings and effect of the microstrip bending discontinuities. The chip is operated for the wide bandwidth of the RF frequency from 22–38GHz. Due to sub-harmonic mixing the required local oscillator frequency (LO) is reduced to half (10–19 GHz) to that of the RF frequency. The conversion gain of the chip is 9– 15 dB and P−1 dB output power is 7–12 dBm. The single sideband and anti-parallel diode pair suppress the in-band unwanted sideband and second harmonic of the local oscillator (2LO), respectively. The suppression of sideband and 2LO signals is typically 20–35 dB and 20– 30 dB, respectively. The size of the chip is as compact as 4.2 mm2 on a 100 μm-thick GaAs substrate.