Dynamic matching in cascode circuits

Details Dynamic matching in cascode circuits Dynamic matching in cascode circuits

2001-12-18

2004-10-12

Tokar, Michael (Department: 2819)

Amplifiers

With semiconductor amplifying device

Including frequency-responsive means in the signal...

C330S305000, C330S311000

Reexamination Certificate

active

06803824

ABSTRACT:

TECHNICAL FIELD OF THE INVENTION
The invention generally relates to electronics circuits. The invention more particularly relates to dynamic matching in cascode circuits, for example, cascode circuits that are used to provide adjustable gain of an input signal.
BACKGROUND
In analog electronic circuits, amplifiers are constructed in many configurations and have various parametric tradeoffs. Discrete dual gate MOSFET (metal-oxide semiconductor field-effect transistor) based amplifiers have been used as IF (intermediate frequency) amplifiers with adjustable gain. In such amplifiers the two gates of the dual gate MOSFET may be arranged as a common source device (transistor) feeding a common gate device—i.e., as a cascode. The common source transistor receives the input signal and the combination of the common gate and common source transistors control the gain and provide isolation. Such amplifiers have good dynamic range, noise figure and reverse isolation. However, they may suffer from distortion at low gain settings and their input impedance may vary with gain.
There is a need to provide amplifiers having controllable gain, good dynamic range, noise figure and reverse isolation but also suitable for higher operating frequencies (microwave rather than IF) and having excellent input match at both high and low gain settings.
SUMMARY OF THE INVENTION
Accordingly, the invention provides amplifiers with superior performance and input matching. Such an amplifier may be implemented as an IC (integrated circuit) with CMOS (complementary metal-oxide semiconductor) or other semiconductor technologies such as GaAs (Gallium Arsenide). High operating frequency (e.g., microwave) may be supported through LSI (large scale integration), as is well-known in the art. Superior performance results from aspects of the novel designs.
According to a first aspect of the invention, a method for improving an input match in a circuit is presented. The method may comprise: operating a cascode having a stage gain controlled by a level setting gain control voltage and operating an impedance compensating circuit. The impedance compensating circuit may controlled by the same level setting gain control voltage.
According to a further aspect of the invention, a circuit for processing a signal comprising is presented. The circuit may include a cascode, a gain controller controlling a gain of the cascode; and an impedance controller loading an input impedance of the cascode with a loading impedance responsive to the control signal. The circuit may operate with adjustable gain and compensated impedance.


REFERENCES:
patent: 3997852 (1976-12-01), Schornack et al.
patent: 5898168 (1999-04-01), Gowda et al.
patent: 6127886 (2000-10-01), Khabbaz et al.
patent: 6163215 (2000-12-01), Shibata et al.
patent: 6172549 (2001-01-01), Gilbert
patent: 6292060 (2001-09-01), Yeo et al.
patent: 6304145 (2001-10-01), Laureanti et al.
patent: 6313705 (2001-11-01), Dening et al.
patent: 6417734 (2002-07-01), Luo et al.
patent: 6492872 (2002-12-01), Fujioka et al.

Affiliated with

Also associated with

Rating

Dynamic matching in cascode circuits does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Dynamic matching in cascode circuits, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamic matching in cascode circuits will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3324929