Highly integrated miniature-sized single sideband subharmonic Ka-band up-converter

A highly integrated up-converter MMIC is presented for low cost and high performance Ka-band transmitter module application. The multiple functions of the up-converter, such as local oscillator (LO) amplifier, single sideband subharmonic mixer, LO bandstop filter, and three-stage RF amplifier, are integrated into a single chip. A proper circuit topology for the complete integrated circuit is selected to achieve the miniature chip size. The combination of lumped and microstrip lines are used to realize the compact sub-circuits. The layout of the circuit is optimized using electromagnetic (EM) simulations. The chip is fabricated in WIN 0.15 μm PHEMT technology on 4-mil GaAs substrate with a layout area of only 2.8 mm × 0.8 mm (2.24 mm²). Measured conversion gain is 12 ± 1 dB over 28-37 GHz for the LO pumping power of 0 dBm. The sideband and 2 × LO suppressions are above 20 dBc. The 1 dB gain compression output power (P-1 dB) is 12 dBm and LO to RF isolation is above 35dB.