Transceiver Three-Port Network Sub-Quarter Wavelength Isolation
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Solution Overview
Problem
Designing silicon-based transmit/receive (TR) switches for wireless communication systems at millimeter wave frequencies is challenging due to RF signal coupling, leading to increased insertion loss and decreased port isolation, which complicates the design of CMOS TR switches at microwave frequencies.
Innovation Solution
A transceiver circuit incorporating a three-port network with a transmission line of length less than a quarter wavelength, allowing the transmitter and receiver to share an antenna while maintaining isolation through a control switch, reducing circuit area and signal loss by isolating the low noise amplifier from the power amplifier during transmission and vice versa during reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a quarter-wavelength transmission line is used to isolate transmitter and receiver, then port isolation is improved, but insertion loss increases and circuit area expands
Solution Approach 1:
The patent changes the transmission line length parameter from the conventional quarter-wavelength to a shorter length (less than quarter-wavelength), which fundamentally alters the isolation mechanism. This parameter change reduces the physical length of the transmission line, thereby decreasing insertion loss and circuit area while maintaining isolation through alternative design configurations of the three-port network
Solution Approach 2:
The patent segments the traditional quarter-wavelength isolation structure into a shorter transmission line combined with a specifically designed three-port network. This segmentation allows the isolation function to be achieved through a different architectural approach that doesn't require the full quarter-wavelength length, thus reducing overall circuit area and insertion loss
2Reliability
If a quarter-wavelength transmission line is used to isolate transmitter and receiver, then port isolation is improved, but circuit area increases
Solution Approach 1:
By changing the transmission line length parameter from quarter-wavelength to a shorter length, the patent directly reduces the physical space required for the transmission line. This parameter modification, combined with an optimized three-port network configuration, achieves the same isolation function in a smaller circuit footprint
Solution Approach 2:
The patent transitions from a conventional two-dimensional layout optimized for quarter-wavelength lines to a redesigned three-port network configuration that achieves isolation through a different spatial arrangement. This dimensional reconfiguration allows for more efficient space utilization and reduced circuit area
3Productivity
If silicon-based TR switches are designed at millimeter wave frequencies, then wireless communication performance is improved, but RF signal coupling increases leading to decreased port isolation
Solution Approach 1:
The patent applies local quality optimization by designing the three-port network with specific characteristics tailored for millimeter wave frequencies. The transmission line and switching elements are locally optimized to handle high-frequency signals while minimizing coupling effects, thereby maintaining port isolation despite the challenges of millimeter wave operation
Solution Approach 2:
The three-port network acts as an intermediary structure that mediates between the transmitter and receiver at millimeter wave frequencies. This intermediate configuration provides controlled isolation and signal routing, preventing direct coupling between transmit and receive paths while enabling efficient wireless communication
Data Source
AI summary
The transceiver has a transmitter, a receiver, and a three-port network. The transmitter is configured to transmit an outgoing RF signal. The receiver is configured to receive an incoming RF signal. The three-port network includes: a transmission line, configured to have a line length less than a quarter of a wavelength of the incoming RF signal; an antenna port, configured to connect to an antenna; a receiver port, configured to connect the receiver to the antenna port; and a transmitter port, configured to connect the transmitter to the antenna port and the receiver port through the transmission line.