Title :
Comparative analysis of InGaP/GaAs HBT differential Colpitts VCOs
Author :
Shrestha, Bhanu ; Wang, Cong ; Kim, Nam-Young
Author_Institution :
RFIC Center, Kwangwoon Univ., Seoul
Abstract :
Two VCOs were fabricated and characterized for ICS application using InGaP/GaAs HBT technology. The cross coupled configuration achieved low phase noise of-130.3 dBc/Hz at 1 MHz offset from the carrier frequency (1.566 GHz), and the double cross coupled structure achieved excellent phase noise of-134.58 dBc/Hz at 1 MHz offset from the carrier frequency (1.630 GHz). Optimized feedback capacitors (CI and C2) ratio were used to improve wanted output wave form. The second VCO exhibited better characteristics when compared with the first one due to faster switching action and relaxation start-up state.
Keywords :
III-VI semiconductors; capacitors; circuit feedback; gallium arsenide; heterojunction bipolar transistors; indium compounds; phase noise; voltage-controlled oscillators; HBT differential Colpitts VCO; InGaP-GaAs; carrier frequency; double cross coupled structure; frequency 1 MHz; heterojunction bipolar transistors; optimized feedback capacitors; phase noise; Capacitors; Coupling circuits; Feedback; Frequency; Gallium arsenide; Heterojunction bipolar transistors; Phase noise; Power generation; Voltage control; Voltage-controlled oscillators;
Conference_Titel :
Microwave Conference, 2008. APMC 2008. Asia-Pacific
Conference_Location :
Macau
Print_ISBN :
978-1-4244-2641-6
Electronic_ISBN :
978-1-4244-2642-3
DOI :
10.1109/APMC.2008.4958382
