Variable impedance load for a variable gain radio frequency amplifier
AssigneeQUALCOMM Incorporated
InventorKenneth Barnett
Life of this patent
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Abstract
A variable impedance load (104) is provided at the output of a radio frequency (RF) driver amplifier (102) having a variable gain. In an exemplary embodiment, the variable load (104) comprises a resistor (R) in series with a semiconductor device (M1). The semiconductor device (M1) has an impedance level determined by a drive current. The value of the drive current is related to the gain of the RF driver amplifier (102).
Claims23
A radio frequency (RF) output circuit for wireless communication, comprising:
- a variable gain RF amplifier having an input, an output, and a gain control input to control amplifier gain;
- and
- a variable impedance load coupled to the amplifier output, the load having an impedance level related to the amplifier gain.
A radio frequency (RF) output circuit for wireless communication, comprising:
- RF amplifier means having an input, an output, and a gain control input to control amplifier gain;
- load means coupled to the amplifier output;
- and
- control means coupled to the load means for varying an impedance of the load means based on the amplifier gain.
A method of compensating for output impedance variation in a radio frequency (RF) output circuit for wireless communication, comprising:
- varying a gain in an RF amplifier;
- coupling a load coupled to an output of the RF amplifier;
- and
- varying an impedance level of the load based on the amplifier gain.
Dependencies are inferred from the claim text.