Efficient AC coupled CMOS RF amplifier

Details Efficient AC coupled CMOS RF amplifier Efficient AC coupled CMOS RF amplifier

2001-04-02

2003-05-27

Nguyen, Patricia (Department: 2817)

Amplifiers

With semiconductor amplifying device

Including push-pull amplifier

C330S267000, C330S277000

Reexamination Certificate

active

06570450

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates generally to semiconductor RF amplifiers, and more particularly the invention relates to a CMOS semiconductor amplifier which has improved operating efficiency.
Cascaded multistage amplifiers are used to create power gain for a small (e.g., 200 mV) high frequency RF signal. Class A amplifiers, which draw current continuously, are needed for small input signals but are inefficient in operation. Class AB amplifiers do not draw current continuously but require larger input signals for efficient operation. Thus, a class A amplifier stage has typically been used with small signals to provide larger signals to following class AB amplifier stages.
The present invention is directed to providing a more efficient small signal amplifier by using only Class AB amplifier stages.
SUMMARY OF THE INVENTION
In accordance with the invention a CMOS RF amplifier is provided for amplifying a small input signal by first providing DC bias voltages to the CMOS transistor gates, and capacitively coupling a small input signal to the voltage biased gates. In effect, the small input signal becomes a larger gate voltage in driving the RF amplifier in an AB operation mode.
In a preferred embodiment, the DC bias voltages are taken from a P transistor which is approximately identical to the P transistor of the CMOS transistor pair, the P transistor being connected to a current source for generating a gate voltage that is resistively coupled to the gate of the P channel transistor of the CMOS transistor pair. Similarly, a N channel transistor is connected with a current source for generating a gate voltage which is resistively coupled to the gate of the N transistor of the CMOS transistor pair. The N channel transistors are approximately identical in structure.
The invention and objects and features thereof will be more readily apparent from the following detailed description and dependent claims when taken with the drawings.


REFERENCES:
patent: 4352073 (1982-09-01), Leuthold
patent: 4403198 (1983-09-01), Muller
patent: 4797630 (1989-01-01), Brown
patent: 4996499 (1991-02-01), Zarabadi et al.
patent: 5568093 (1996-10-01), Holzer

Affiliated with

Also associated with

Rating

Efficient AC coupled CMOS RF amplifier does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Efficient AC coupled CMOS RF amplifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient AC coupled CMOS RF amplifier will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3050681