A 802.11a WLAN oscillator with high Q embedded passives on laminate-type organic package

Phase noise, output RF amplitude, and jitter are the oscillator performance characteristics which are determined by the DC power consumed and the quality factor (Q) of the passives. In a multi-standard environment, low phase noise enables achieving high SNR for all standards in the presence of noise and interference. CMOS and similar IC technologies limit the DC voltage supply and provide very low Q inductors and capacitors (∼6 to 30), trading the oscillator´s performance with the DC power consumed. The paper presents a low power, low phase noise Colpitt´s oscillator at 5.2 GHz for WLAN (IEEE 802.11a) application. The adjacent channel interference suppression requirement of the 802.11a WLAN system (5.15-5.35 GHz, 5.725-5.825 GHz) is approximately 25 dB with an SNR of 19 dB for a BER of 10^-6 in a 64 QAM system. This leads to a phase noise requirement of at least -110 dBc/Hz at 1 MHz offset (Bhattacharjee, J. et al., 2002 IEEE MTT-S Int. Microwave Symp. Dig., vol.1, p.585-8, 2002).