A polyphase filter based on CMOS inverters

• A new idea for generation of quadrature signals on chip is presented. The topology is based on a passive RC polyphase filter, where the resistive parts are made active by using inverters. The active filter combines quadrature generation, isolation, and gain without losing quadrature performance compared to a regular RC polyphase filter. The filter technique is demonstrated in a 10GHz front-end application where a broadband VCO drives an active polyphase filter to generate quadrature LO signals. By avoiding a quadrature VCO and tuned buffers, significant reductions in chip area are possible

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

active filter

quadrature generation

10 GHz

passive RC filter

tuned buffers

quadrature LO signals

voltage controlled oscillator

polyphase filter

CMOS inverters

Publication and Content Type

kon (subject category)

ref (subject category)