All MOSCAP Based Continuously Tunable Filter

Rakesh Kumar Palani, Ramesh Harjani

Research output: Chapter in Book/Report/Conference proceedingChapter


This chapter presents an inverter based filter design that uses only MOSCAP as filter capacitors. Further in the design the load capacitance compensates the negative feedback network allowing the majority of current to flow into the load. This results in an increase in the overall power efficiency. As a proof of concept, a third order inverter based 34–314 MHz tunable continuous time channel select filter for software-defined radios is fabricated in TSMC’s 65 nm technology. By using the high density tunable MOSCAPs at a low swing node, the filter achieves an OIP3 of +25.24 dBm while drawing 4.2 mA from a 1.1 V supply and occupies an area of 0.007 mm2. The measured intermodulation distortion varies by 5 dB across a 120 variation in temperature and 6.5 dB across a 200 mV variation in power supply. Further, the filter presents a high impedance node at the input and a low impedance node at the output easing system integration.

Original languageEnglish (US)
Title of host publicationAnalog Circuits and Signal Processing
Number of pages15
StatePublished - 2017

Publication series

NameAnalog Circuits and Signal Processing
ISSN (Print)1872-082X
ISSN (Electronic)2197-1854

Bibliographical note

Publisher Copyright:
© 2017, Springer International Publishing AG.


  • General Purpose Technology
  • Intermodulation Distortion
  • Output Impedance
  • Source Follower
  • Tuning Range


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