Low-noise amplifier with switched gain and method
AssigneeInfineon Technologies AG
InventorsRobert Grant Irvine, Samuel Alfred Tiller
Life of this patent
Estimating the term…
Abstract
A low noise radio frequency amplifier is switchable between a low gain state and a high gain state. A first, common-emitter transistor is active in the high gain state and inactive in the low gain state. The first transistor has a base coupled to a radio frequency input and a first bias input, an emitter coupled to ground, and a collector coupled to an amplified radio frequency output. A second, common-base transistor is active in the low gain state and inactive in the high gain state. The second transistor has an emitter coupled to the radio frequency input, a base coupled to a second bias input, and a collector coupled to the amplified radio frequency output.
Claims22
A radio frequency amplifier having a low gain state and a high gain state comprising:
- a first transistor active in the high gain state and inactive in the low gain state, said first transistor having a base coupled to a radio frequency input and a first bias input, an emitter coupled to ground, and a collector coupled to an amplified radio frequency output;
- and
- a second transistor active in the low gain state and inactive in the high gain state, said second transistor having an emitter coupled to said radio frequency input, a base coupled to a second bias input, and a collector coupled to said amplified radio frequency output.
A method of amplifying a radio frequency signal comprising the steps of:
- amplifying said radio frequency signal using a high-gain, common-emitter transistor;
- switching said high-gain common-emitter transistor off;
- and
- amplifying said radio frequency signal using a low-gain, common-base transistor.
A switched gain radio frequency amplifier, comprising:
- a radio frequency input and an amplified radio frequency output;
- high amplification means coupled to said radio frequency input and coupled to said radio frequency output;
- low amplification means coupled to said radio frequency input and coupled to said radio frequency output;
- intermediate amplification means coupled to said radio frequency input and coupled to said radio frequency output;
- and
- control means for switching between said high, low and intermediate amplification means.
A switched gain radio frequency amplifier, comprising:
- a radio frequency input and an amplified radio frequency output;
- high amplification means coupled to said radio frequency input and coupled to said radio frequency output;
- low amplification means comprising an NPN common-base bipolar transistor coupled to said radio frequency input and coupled to said radio frequency output;
- and
- control means for switching between said high and low amplification means.
A switched gain radio frequency amplifier, comprising:
- a radio frequency input and an amplified radio frequency output;
- a high-gain amplifier having an input coupled to said radio frequency input and an output coupled to said radio frequency output, and having an input coupled to a first bias signal;
- a low-gain amplifier comprising an NPN common-base bipolar transistor having an input coupled to said radio frequency input and an output coupled to said radio frequency output, and having an input coupled to a second bias signal;
- said high and low gain amplifiers having an active state and an inactive state;
- said first bias signal for switching said high gain amplifier between said active and inactive state;
- and
- said second bias signal for switching said low gain amplifier between said active and inactive state.
Dependencies are inferred from the claim text.