A Ka band FMCW Transmitter with a High Ratio Multiplier

Abstract

This work presents a Ka band FMCW transmitter equipped with a high ratio frequency multiplier, which can be easily driven by the DDS (Direct Digital Synthesis) without PLLs. The transmitter is composed of a two-stage x35 frequency multiplier and a two-stage power amplifier (PA). The first stage of the frequency multiplier is a 5-phase ring-VCO-based injection locked frequency multiplier with a ratio of 7. The second stage is a 5-push frequency multiplier combining the 5-phase outputs of the ring cells in the first stage. The final output of 35 GHz is amplified by the transformer coupled two-stage amplifier which provides the output power of 14.1 dBm. The total power consumption is 309.56mW and 1GHz offset spur is lower than 24dBc. Measured phase noise at 35GHz at 1MHz offset is - 103.3dBc/Hz. © 2022 IEEE.