Transceiver Arrangement with Phase Shifters for FDD Interference
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Solution Overview
Problem
Existing transceiver arrangements face challenges in minimizing transmitter signal interference at the receiver input during frequency division duplex communication, particularly due to internal interference and the inefficiency of traditional duplexer solutions which are costly, space-consuming, and difficult to implement on-chip.
Innovation Solution
A transceiver arrangement utilizing a filtering structure and a phase shifter structure with 180° phase shifters and filters of different types to effectively attenuate transmitter signals at the receiver input, reducing signal loss and maintaining operation independence from antenna impedance changes.
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 device complexity, cost, and space consumption increase
Solution Approach 1:
The transceiver signal path is segmented into multiple separate paths (first signal path, second signal path, third signal path, fourth signal path) with dedicated filters and phase shifters for each path. This segmentation allows independent optimization of each path's filtering and phase control characteristics, achieving effective interference cancellation without requiring a complex monolithic duplexer structure.
Solution Approach 2:
Dummy loads are introduced as intermediary elements connected to the transmitter output through filtering arrangements. These dummy loads receive a portion of the transmitter signal and return a phase-inverted version that cancels the interference at the receiver input. This intermediary approach provides effective isolation without requiring direct transmitter-receiver isolation components like traditional duplexers.
2Object-affected harmful factors
If a dummy load is used to achieve electrical balance and suppress transmitter contribution at receiver input, then signal cancellation is improved, but signal energy loss increases
Solution Approach 1:
Different signal paths are assigned different filter types with specific frequency characteristics. First type filters pass transmitter frequency while attenuating receiver frequency, while second type filters do the opposite. This local differentiation of filter characteristics across parallel paths enables selective interference cancellation while preserving desired signal energy in the main reception path.
Solution Approach 2:
The signal paths are arranged asymmetrically with respect to filter placement and phase shifting. The first and second signal paths use different filter combinations compared to the third and fourth paths, creating asymmetric phase and amplitude relationships that enable targeted cancellation of transmitter leakage while maintaining receiver signal integrity.
3Object-affected harmful factors
If traditional duplexer solutions are implemented, then transmitter-receiver isolation is improved, but manufacturing cost and space consumption increase
Solution Approach 1:
The filtering arrangements incorporate controllable filters with adjustable parameters that can be dynamically tuned based on operating conditions. This dynamic adaptability allows the system to maintain effective interference cancellation across varying frequencies and impedance conditions, providing duplexer-like performance without the fixed, bulky structure of traditional duplexers.
Solution Approach 2:
The interference cancellation is achieved by adding a temporal dimension through phase shifting (180° phase difference) rather than relying solely on spatial separation. By manipulating the phase dimension of the signals through controllable phase shifters, the system achieves isolation equivalent to physical separation but in a compact, integrable form suitable for on-chip implementation.
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 efficiently reduces transmitter signal interference at the receiver input, achieving effective signal cancellation and isolation across a wide bandwidth, independent of antenna impedance, while minimizing signal loss and avoiding the limitations of traditional duplexer solutions.
Implementation Method 1
a phase shifter arrangement which comprises a first 180° phase shifter and a second 180° phase shifter
Implementation Method 2
The filtering arrangement comprises filters of a first type and filters of a second type. The filters of the first type are arranged to pass signals at transmitter frequency and attenuate signals at receiver frequency, and the filters of the second type are arranged to attenuate signals at transmitter frequency and pass signals at receiver frequency
Implementation Method 3
Transceivers can also be operated in full duplex, i.e. the receiver and transmitter operate simultaneously wherein some special arrangements are provided to prevent the transmitter from concealing the received signal. One approach to achieve this is to assign different frequencies for transmission and reception.
Data Source
AI summary
A transceiver arrangement is disclosed. The transceiver arrangement comprises a receiver arranged for frequency-division duplex communication with a communication network and a transmitter arranged for frequency-division duplex communication with the communication network. The transceiver arrangement also comprises a transmission port anda phase shifter arrangement which comprises a first 180° phase shifter and a second 180° phase shifter. The transceiver arrangement further comprises a filtering arrangement. The filtering arrangement comprises filters of a first type and filters of a second type. The filtering arrangement and the phase shifter arrangement are arranged to connect the receiver, transmitter and transmission port forming a first signal path between the transmission port and the transmitter by a first one of the filters of the first type and the first phase shifter in series, a second signal path between the transmission port and the transmitter by a second one of the filters of the first type and a first one of the filters of the second type in series, a third signal path between the transmission port and the receiver by a second one of the filters of the second type and the second phase shifter in series, and a fourth signal path between the transmission port and the receiver by a third one of the filters of the second type and a third one of the filters of the first type in series. The filters of the first type are arranged to pass signals at transmitter frequency and attenuate signals at receiver frequency, and the filters of the second type are arranged to attenuate signals at transmitter frequency and pass signals at receiver frequency. A communication device capable of frequency division duplex communication comprising such a transceiver arrangement is also disclosed.