RADIO FREQUENCY TRANSCEIVER FRONT END CIRCUIT WITH PARALLEL RESONANT CIRCUIT
First Claim
1. A front end circuit for coupling an antenna to a radio frequency (RF) transceiver including a transmit line, a receive line, a first enable line, and a second enable line, the front end comprising:
- an antenna port;
a power amplifier with a signal output, a signal input coupled to the transmit line of the transceiver and a first control circuit coupled to the first enable line of the transceiver, a first voltage applied to the first control circuit activating and setting a bias point of the power amplifier;
a low noise amplifier with a signal input, a signal output coupled to the receive line of the transceiver and a second control circuit coupled to the second enable line of the transceiver, a second voltage applied to the second control circuit activating and setting a bias point of the low noise amplifier;
a matching network coupled to the antenna port, the signal output of the power amplifier and the signal input of the low noise amplifier, the signal output of the power amplifier and the signal input of the low noise amplifier being common; and
a parallel resonant circuit connected between the low noise amplifier and the power amplifier.
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Accused Products
Abstract
A front end circuit for coupling an antenna to a radio frequency (RF) transceiver for time domain duplex systems is disclosed. The front end circuit includes an antenna port, a power amplifier, a low noise amplifier, and a matching network. The output of the power amplifier and the input of the low noise amplifier are coupled to the matching network and connected in common to the antenna. The power amplifier and the low noise amplifier are activated and deactivated in sequence corresponding to the transmit and receive modes of the transceiver, and the matching network minimizes the effect that one has on the other at the designated operating frequency.
40 Citations
27 Claims
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1. A front end circuit for coupling an antenna to a radio frequency (RF) transceiver including a transmit line, a receive line, a first enable line, and a second enable line, the front end comprising:
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an antenna port; a power amplifier with a signal output, a signal input coupled to the transmit line of the transceiver and a first control circuit coupled to the first enable line of the transceiver, a first voltage applied to the first control circuit activating and setting a bias point of the power amplifier; a low noise amplifier with a signal input, a signal output coupled to the receive line of the transceiver and a second control circuit coupled to the second enable line of the transceiver, a second voltage applied to the second control circuit activating and setting a bias point of the low noise amplifier; a matching network coupled to the antenna port, the signal output of the power amplifier and the signal input of the low noise amplifier, the signal output of the power amplifier and the signal input of the low noise amplifier being common; and a parallel resonant circuit connected between the low noise amplifier and the power amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A radio frequency (RF) transceiver front end circuit with a predefined operating frequency for connecting a transceiver to an antenna, the front end comprising:
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an antenna port connectible to the antenna; a transmit port; a receive port; a low noise amplifier connected to the receive port and including a first low noise amplifier transistor; a power amplifier connected to the transmit port and including a first power amplifier transistor having a base coupled to the transmit port, a collector, and an emitter; a power amplifier control circuit with a first adjustable voltage source coupled to the base of the first power amplifier transistor, the power amplifier control circuit activating and setting a bias point of the first power amplifier transistor; a matching circuit including a power amplifier output matching segment coupled to the power amplifier and the antenna port, and a low noise amplifier input matching segment coupled to the first low noise amplifier transistor and the antenna port, the power amplifier matching segment having shared components with the low noise amplifier segment; and a parallel resonant circuit including a switching transistor with a base coupled to the power amplifier control circuit, an emitter coupled to the collector of the power amplifier transistor, and a collector coupled to an intermediate point in the low noise amplifier input matching segment of the matching circuit. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification