Design of Q-band Transmitter RF Front-End Module

This paper presents a Q-band transmitter (Tx) RF front-end module which, includes a PLL, a lowpass filter and an up-converter. The PLL provides about 10 dBm of output power at 9.5996 GHz. The phase noise of PLL is better than -98 dBc/Hz offset 1 kHz. In order to suppress the harmonic frequency, the PLL is integrated with lowpass filter. The filter is variable-width stepped impedance filter and its IL is less than 1 dB at 9.6 GHz and the harmonic suppression is better than 25 dB. The fourth harmonic up-converter is used to convert signal to Q-band. The proposed Tx module is measured under the single tone and modulated signal. The IF frequency is 5.775GHz which output is 10 dBm. The LO signal is provided with PLL. The RF signal is 24.86 dBm at 44.1734 GHz. The modulated signal adopts 802.11ac with 80MHz, the measured channel power is -26.12 dBm and the EVM is 6.9% at 64 QAM.