E-Band Active Upconverter Module with Tunable LO Feedthrough

This paper presents an E-band multi-chip transmitter module with the capability of tuning the LO feedthrough to improve the signal quality for broadband wireless communication purposes. The module contains two millimeter-wave monolithic integrated circuits, an upconverter and an amplifier chip in a 50 nm InGaAs-based metamorphic high electron mobility transistor technology. The upconverter chip has the capability of controlling the local oscillator isolation behavior over frequency with voltage-controlled Lange couplers, which create the differential quadrature I and Q. Regarding the ITU recommendation and ETSI standard for fixed-point terrestrial wireless links, the transmitter module can be optimized either for the downlink or the uplink band. An LO isolation of above 40 dB could be achieved with tuning at 73.5 GHz in comparison to 10 dB with the control-voltage set for 83.5 GHz. The EVM quality for complex modulated data increases from -22.5 dB to -25.2 dB for a 16QAM baseband data signal with a baudrate of 2.5 GBd.