Title :
Balanced log-domain filters for VHF applications
Author :
El-Gamal, Mourad ; Leung, Vincent ; Roberts, Gordon W.
Author_Institution :
Microelectron. & Comput. Syst. Lab., McGill Univ., Montreal, Que., Canada
Abstract :
General transfer characteristics of log-domain integrators necessary to realize different log-domain filter topologies, based on LC ladder synthesis, are described. As an example, a transistor-level all-NPN differential log-domain integrator is proposed and used to implement a fully tunable balanced 600 MHz biquad. The integrator is then used to implement 4th and 6th-order balanced bandpass filters. The sensitivity of log-domain integrators to DC biasing offsets is discussed. These offsets are minimized using a BiCMOS common mode feedback circuit. Simulation results are presented with an emphasis on distortion analysis
Keywords :
BiCMOS analogue integrated circuits; VHF filters; band-pass filters; biquadratic filters; circuit feedback; circuit tuning; integrating circuits; ladder filters; 600 MHz; BiCMOS common mode feedback circuit; DC biasing offsets; LC ladder synthesis; VHF applications; balanced bandpass filters; balanced log-domain filters; distortion analysis; fully tunable biquad; log-domain integrators; transfer characteristics; transistor-level all-NPN differential integrator; Application software; Band pass filters; Equations; Filtering; Frequency; Laboratories; Microelectronics; Nonlinear filters; Tunable circuits and devices; Voltage;
Conference_Titel :
Circuits and Systems, 1997. ISCAS '97., Proceedings of 1997 IEEE International Symposium on
Print_ISBN :
0-7803-3583-X
DOI :
10.1109/ISCAS.1997.608780
