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.