Transceiver Arrangement Adaptive Impedance Common-Mode Rejection
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Solution Overview
Problem
Existing transceiver designs for frequency division duplex communication face challenges in minimizing internal interference between transmitter and receiver signals, particularly due to the cost, space consumption, and implementation difficulties of duplexers, which result in significant insertion loss.
Innovation Solution
A transceiver arrangement combining filtering and cancelling structures with an adaptive impedance circuit, utilizing filters and a transformer to attenuate and reject transmitter signals at the receiver input, while an adaptive resistance provides adjustable impedance to minimize transmitter energy reaching the receiver, thereby achieving common-mode rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a duplexer is used to separate transmitter and receiver signals, then signal isolation is improved, but cost, space consumption, and device complexity increase
Solution Approach 1:
The duplexer function is segmented into two separate filters: a first filter connected to the transmitter output that passes transmitter frequency and attenuates receiver frequency, and a second filter connected to the receiver input that attenuates transmitter frequency and passes receiver frequency. This segmentation eliminates the need for a single complex duplexer while achieving similar signal isolation.
Solution Approach 2:
The patent introduces an adaptive impedance circuit as an intermediary element between the transmitter and receiver paths. This circuit provides adjustable resistance to optimize the cancellation of transmitter signals at the receiver input, acting as a mediator that enhances signal isolation without requiring a traditional duplexer structure.
2Object-affected harmful factors
If a dummy load is used to achieve electrical balance, then transmitter signal suppression at receiver input is improved, but insertion loss increases
Solution Approach 1:
The patent employs an adaptive impedance circuit that dynamically adjusts its resistance parameter to optimize transmitter signal suppression. By changing the impedance parameter adaptively rather than using a fixed dummy load, the system achieves effective transmitter signal cancellation at the receiver input while minimizing insertion loss for legitimate receiver signals.
Solution Approach 2:
The dummy load is replaced with an adaptive impedance circuit that provides dynamic impedance adjustment. This dynamic element can change its characteristics based on operating conditions, allowing optimal suppression of transmitter signals while maintaining low insertion loss for receiver signals, unlike a static dummy load.
3Object-affected harmful factors
If filters are used to separate frequencies, then signal isolation is improved, but device complexity and component count increase
Solution Approach 1:
The first and second filters are designed to perform multiple functions: frequency separation, signal isolation, and impedance matching. The adaptive impedance circuit also serves dual purposes by providing both impedance matching and dynamic cancellation of transmitter signals. This multi-functionality reduces the need for additional components while maintaining effective signal isolation.
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 solution effectively reduces transmitter energy at the receiver input to near zero, minimizing insertion loss and improving the efficiency of frequency division duplex communication by using a combination of filtering and adaptive impedance techniques.
Implementation Method 1
a first filter connected between an output of the transmitter and the transmission port and arranged to pass signals at transmitter frequency and attenuate signals at receiver frequency
Implementation Method 2
a second filter connected between another of the terminals of the primary winding and a reference voltage and arranged to attenuate signals at transmitter frequency and pass signals at receiver frequency
Implementation Method 3
a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port
Implementation Method 4
an adaptive impedance circuit arranged to provide an adjustable resistance, connected between the output of the transmitter and the junction between the second filter and the another of the terminals of the primary winding, and arranged to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at receive frequency
Data Source
AI summary
A transceiver arrangement comprises a receiver arranged for frequency-division duplex communication with a communication network; a transmitter arranged for frequency-division duplex communication with the communication network; a transmission port for connecting to an antenna or wire; a first filter connected between an output of the transmitter and the transmission port and arranged to pass signals at transmitter frequency and attenuate signals at receiver frequency; a transformer having a primary winding and a secondary winding, wherein the primary winding has one of its terminals connected to the transmission port; a second filter connected between another of the terminals of the primary winding and a reference voltage and arranged to attenuate signals at transmitter frequency and pass signals at receiver frequency; and an adaptive impedance circuit arranged to provide an adjustable resistance, connected between the output of the transmitter and the junction between the second filter and the another of the terminals of the primary winding, and arranged to provide a contribution from the transmitter to the primary winding such that a common-mode rejection of a contribution from the transmitter provided at the transmission port occurs at receive frequency. A communication device, a method of controlling a transceiver arrangement, and a computer program are also disclosed.