Title :
A 3-V analog FM-modulator based on a delay-modulated PLL synthesizer
Author :
Rahkonen, Timo ; Tammelin, Saila ; Kostamovaara, Juha
Author_Institution :
Electron. Lab., Oulu Univ., Finland
Abstract :
An analog FM modulator operating within the loop bandwidth of a frequency synthesizer is presented. Its operation is based on modulating the propagation delay of the reference frequency of the synthesizer PLL, thus causing phase modulation in the synthesized carrier. The modulator circuit is implemented in a 1.2 um BiCMOS process, has 2.8 V supply voltage and 1.5 mA supply current. In the in-system tests, the modulator showed 7 KHz/V gain, 20 Hz(rms) residual FM and -31.-37 dB THD on audio band. Requirements for the modulator are discussed
Keywords :
BiCMOS analogue integrated circuits; frequency modulation; frequency synthesizers; integrated circuit noise; modulators; phase locked loops; 1.2 mum; 1.5 mA; 2.8 V; 20 Hz; 3 V; BiCMOS process; analog FM-modulator; delay-modulated PLL synthesizer; frequency synthesizer; in-system tests; loop bandwidth; modulator circuit; phase modulation; propagation delay; reference frequency; residual FM; Bandwidth; BiCMOS integrated circuits; Circuit synthesis; Current supplies; Frequency modulation; Frequency synthesizers; Phase locked loops; Phase modulation; Propagation delay; Voltage;
Conference_Titel :
Circuits and Systems, 1997. Proceedings of the 40th Midwest Symposium on
Conference_Location :
Sacramento, CA
Print_ISBN :
0-7803-3694-1
DOI :
10.1109/MWSCAS.1997.666196
