A Novel Harmonic Noise Frequency Filtering Vco For Optimizing Phase Noise

InGaP/GaAs HBT LC-VCOs designed with and without the proposed Harmonic Noise Frequency Filtering (HNFF) technique are presented here. To optimize phase noise, the HNFF technique is compared using noise frequency filtering capacitors. The HNFF-VCO produced ultra low phase noise performance. The tuning range of this VCO is 261 MHz with an output power of -10.25 dBm at 1.721 GHz carrier. Furthermore, the phase noise of this VCO -133.96 dBc/Hz at 1 MHz offset. The HNFF-VCO is designed with a total chip area of 0.9 X 0.9 mm(2). Its phase noise performance is enhanced by 8.9 dBc at 1 MHz offset by comparison with a N-VCO without the HNFF technique.