Integrated Compact Broad Ka-Band Sub-Harmonic 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 anti-parallel 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 22-38 GHz. 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-1dB 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 mm on a 100 μm-thick GaAs substrate.