Transceiver Auxiliary Amplifier Phase Cancellation for Signal Isolation
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Solution Overview
Problem
Existing transceivers face challenges in full duplex communication due to internal interference between transmitter and receiver signals, particularly when using frequency division duplex (FDD), as duplexers are costly, space-consuming, and difficult to implement on-chip, and existing on-chip solutions like dummy loads result in energy loss through heat dissipation.
Innovation Solution
A transceiver design incorporating a power amplifier, an auxiliary power amplifier with controllable phase shift and gain, and impedance elements, where the auxiliary power amplifier's output is phase-shifted and amplitude-matched to the power amplifier's output, and impedance elements are controlled to suppress transmitter signal contribution at the receiver input, using a feedback mechanism to optimize isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a duplexer is used to separate transmitter and receiver signals, then isolation between signals is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces an intermediary circuit structure consisting of a first impedance element connected between the transmitter output and receiver input, and a second impedance element connected between the auxiliary power amplifier output and receiver input. This intermediary arrangement creates a voltage division mechanism that isolates the transmitter signal from the receiver input without requiring a complex duplexer, thereby achieving signal separation with simpler circuitry.
Solution Approach 2:
The patent employs an auxiliary power amplifier that copies the transmitter signal and applies a phase shift to it. This copied signal is then combined with the original transmitter signal through the impedance elements to create destructive interference at the receiver input, effectively isolating the transmitter signal without needing physical separation components like duplexers.
2Reliability
If a dummy load is used to suppress transmitter signal contribution, then isolation is improved, but energy loss increases
Solution Approach 1:
Instead of dissipating energy as heat in a dummy load, the patent converts the harmful transmitter signal into a beneficial cancellation mechanism. The auxiliary power amplifier generates a phase-shifted copy of the transmitter signal that destructively interferes with the original signal at the receiver input. This transforms the energy that would otherwise be wasted into a useful cancellation effect, achieving isolation without energy loss.
Solution Approach 2:
The patent changes the phase parameter of the auxiliary power amplifier output relative to the transmitter output. By adjusting this phase shift parameter, the system creates destructive interference for the transmitter signal while maintaining constructive interference for the received signal, thereby achieving selective isolation without energy dissipation.
3Productivity
If full duplex communication is implemented with same antenna, then productivity is improved, but internal interference increases
Solution Approach 1:
The patent implements dynamic control of the auxiliary power amplifier phase shift and gain to adapt to varying communication conditions. This dynamic adjustment allows the system to maintain optimal isolation performance across different operating scenarios, enabling full duplex communication with the same antenna while minimizing internal interference through real-time parameter optimization.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces transmitter signal interference at the receiver input, minimizing energy loss and improving transceiver performance in full duplex communication by achieving isolation through voltage division and impedance control, even in varying environmental conditions.
Implementation Method 1
an auxiliary power amplifier which has controllable phase shift and gain
Implementation Method 2
by providing a voltage division between outputs of a power amplifier of a transmitter and an auxiliary power amplifier
Implementation Method 3
the first impedance element is connected between an output of the auxiliary power amplifier and an input of the receiver, the second impedance element is connected between an output of the power amplifier of the transmitter and the input of the receiver
Data Source
AI summary
A transceiver is disclosed comprising a transmitter; a receiver; and a signal transmission arrangement. The transmitter comprises a power amplifier, and the signal transmission arrangement is arranged to transmit signals provided from the transmitter through its power amplifier, and arranged to receive signals and provide them to the receiver. The transceiver further comprises an auxiliary power amplifier which has controllable phase shift and gain; a first impedance element; a second impedance element; and a controller. The auxiliary power amplifier has its input connected to the input of the power amplifier of the transmitter, the first impedance element is connected between an output of the auxiliary power amplifier and an input of the receiver, the second impedance element is connected between an output of the power amplifier of the transmitter and the input of the receiver, and the controller is arranged to control the auxiliary power amplifier to provide a signal that has a phase and amplitude in relation to the output of the power amplifier of the transmitter and the impedances of the first and second impedance elements such that the transmitter contribution at the input of the receiver is suppressed. A method, computer program and communication device is also disclosed.