Title :
An EDGE transmitter with mitigation of oscillator pulling
Author :
Bashir, Imran ; Staszewski, R. Bogdan ; Eliezer, Oren ; Waheed, Khurram ; Zoicas, Vasile ; Tal, Nir ; Mehta, Jaimin ; Lee, Meng-Chang ; Balsara, Poras T. ; Banerjee, Bhaskar
Author_Institution :
Univ. of Texas at Dallas, Richardson, TX, USA
Abstract :
We propose a polar transmitter architecture that is robust to modulation-induced injection pulling of its RF oscillator by means of a built-in self compensation. A mathematical model is presented for the injection pulling mechanism, which incorporates a digitally-controlled delay circuit that minimizes injection pulling by adjusting the overall phase shift in the parasitic path between the final amplitude modulation stage (aggressor) and the RF oscillator (victim). The technique is verified in a 65-nm CMOS GSM/GPRS/EDGE SoC demonstrating compliant error vector magnitude (EVM) and modulation spectral-mask performance over process and temperature.
Keywords :
3G mobile communication; CMOS integrated circuits; amplitude modulation; delay circuits; digital control; packet radio networks; radio transmitters; radiofrequency oscillators; CMOS; EDGE transmitter; GPRS; GSM; RF oscillator; SoC; amplitude modulation stage; built-in self compensation; digitally-controlled delay circuit; error vector magnitude; mathematical model; modulation spectral-mask performance; modulation-induced injection pulling; oscillator pulling mitigation; polar transmitter architecture; Amplitude modulation; CMOS process; Circuits; Delay; GSM; Mathematical model; Oscillators; Radio frequency; Robustness; Transmitters;
Conference_Titel :
Radio Frequency Integrated Circuits Symposium (RFIC), 2010 IEEE
Conference_Location :
Anaheim, CA
Print_ISBN :
978-1-4244-6240-7
DOI :
10.1109/RFIC.2010.5477247
