Low-load-modulation broadband amplifier
AssigneeMACOM Technology Solutions Holdings, Inc.
InventorsBi Ngoc Pham, Kelly Doherty
Life of this patent
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Abstract
Low-load-modulation, broadband power amplifiers and method of use are described. The amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the fully-on and fully backed-off states of the amplifier. With lower load modulation, the power amplifiers described herein exhibit better power-handling capability and RF fractional bandwidth as compared to conventional amplifiers.
Claims27
A power amplifier comprising:
- a main amplifier coupled to a first combining node;
- a first impedance inverter between the main amplifier and the first combining node;
- a first peaking amplifier directly connected to the first combining node;
- a second impedance inverter between the first combining node and a second combining node;
- a second peaking amplifier coupled to the second combining node;
- and
- a third impedance inverter between the second peaking amplifier and the second combining node, wherein:
- the main amplifier outputs an amount of maximum power or current that differs by at least 20% from an amount of maximum power or current output by the first peaking amplifier and outputs the amount of maximum power or current that differs by at least 20% from an amount of maximum power or current output by the second peaking amplifier.
A power amplifier comprising:
- a main amplifier coupled to a first combining node;
- a first impedance inverter between the main amplifier and the first combining node;
- a first peaking amplifier directly connected to the first combining node;
- a second impedance inverter between the first combining node and a second combining node;
- a second peaking amplifier coupled to the second combining node;
- and
- a third impedance inverter between the second peaking amplifier and the second combining node wherein:
- Zo2 is a characteristic impedance for the second impedance inverter;
- Zo3 is a characteristic impedance for the third impedance inverter;
- and
- a ratio of Zo2 and Zo3 substantially satisfies the following relation to within 10%:
- Z
- O
-
- 3
- Z
- O
-
- 2
- =
- (
- i
- m
- +
- i
- 1
- )
- i
- 1
-
- i
- 2
- ,
- where im represents a maximum amount of current output by the main amplifier, i1 represents a maximum amount of current output by the first peaking amplifier, and i2 represents a maximum amount of current output by the second peaking amplifier when the main amplifier, the first peaking amplifier, and the second peaking amplifier are fully amplifying.
A method of operating a power amplifier, the method comprising:
- amplifying, with a main amplifier, a first portion of a received signal;
- providing a first output from the main amplifier to a first impedance inverter;
- receiving, at a first combining node, a first signal from the first impedance inverter;
- amplifying, with a first peaking amplifier arranged in parallel with the main amplifier, a second portion of the received signal;
- receiving, at the first combining node, a second signal from the first peaking amplifier, with the first peaking amplifier being directly connected to the first combining node;
- providing a first combined signal from the first combining node to a second impedance inverter;
- providing an output signal from the second impedance inverter to a second combining node;
- amplifying, with a second peaking amplifier arranged in parallel with the first peaking amplifier, a third portion of the received signal;
- providing an output from the second peaking amplifier to a third impedance inverter;
- receiving, at the second combining node, a third signal from the third impedance inverter;
- and
- outputting, by the main amplifier, an amount of maximum power or current that differs by at least 20% from an amount of maximum power or current output by the first peaking amplifier and outputting, by the main amplifier, the amount of maximum power or current that differs by at least 20% from an amount of maximum power or current output by the second peaking amplifier.
Dependencies are inferred from the claim text.