Transceiver Switch Circuitry Using λ/4 Transformers for Low Loss
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Solution Overview
Problem
Existing transceiver switch circuitry in CMOS technology faces challenges with high insertion loss, low linearity, and narrow bandwidth, particularly in 5G mm-wave transceivers, which can lead to poor Adjacent Channel Leakage Ratio (ACLR) and Error Vector Magnitude (EVM) performance due to non-linear CMOS switches and high voltage levels.
Innovation Solution
A transceiver switch circuitry utilizing λ/4 transmission lines and Doherty amplifiers with integrated impedance matching, incorporating quarter wavelength impedance transformers and switch circuits to minimize insertion loss and enhance linearity, while using passive lumped components to maintain low voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional CMOS switches are used in transceiver circuitry, then the device can be manufactured with standard CMOS technology, but high insertion loss and low linearity occur due to non-linear switch behavior and high voltage levels
Solution Approach 1:
The patent introduces λ/4 transmission lines as intermediary components between the CMOS switches and the signal paths. These transmission lines act as mediators that transform the high-voltage, non-linear switch output into a form that is more suitable for the subsequent circuit stages, thereby reducing insertion loss and improving linearity while maintaining CMOS manufacturability
Solution Approach 2:
The patent changes the electrical parameters of the signal path by using λ/4 transmission lines with specific impedance values. These transmission lines transform the voltage and impedance levels from the CMOS switches, effectively reducing the voltage stress on subsequent components and improving the overall linearity and insertion loss characteristics of the transceiver circuitry
2Power
If high power levels are delivered by the power amplifier, then the transmission output power is sufficient, but high voltage levels damage the receiver circuitry and require additional protection
Solution Approach 1:
The patent extracts the high-voltage signal path from the receiver circuitry by introducing λ/4 transmission lines that isolate the receiver from the high-power amplifier output. The transmission lines are configured to present high impedance to the receiver during transmission mode, effectively taking out the harmful high voltage levels from the receiver path while maintaining full power delivery capability
Solution Approach 2:
The λ/4 transmission lines serve as intermediary components that stand between the high-power amplifier and the receiver circuitry. These intermediaries transform and isolate the high-voltage signals, protecting the receiver from voltage damage while allowing the amplifier to deliver full power to the antenna during transmission mode
3Power
If impedance matching is performed with high impedance transmission lines, then the power amplifier can deliver high output power, but the bandwidth is limited and external filtering is required
Solution Approach 1:
The patent makes the λ/4 transmission lines multi-functional by designing them to provide both impedance matching for high power delivery and inherent broadband filtering characteristics. The transmission lines are configured to work across a wide frequency range without requiring external filtering components, thereby achieving both high power output and broadband operation with a single integrated solution
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
The solution achieves low transmission and reception insertion loss, high isolation, and improved linearity, reducing the need for stacked MOS devices and external filtering, thus enhancing the efficiency and performance of transceiver switches in wireless communication.
Implementation Method 1
a first quarter wavelength, λ/4, impedance transformer and a first switch circuitry configured to ground the first quarter wavelength, λ/4, impedance transformer at the receiver port in the transmission mode
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
A transceiver switch circuitry (30) comprising an antenna port (18), a receiver port (17), a first transmitter port (15) and a second transmitter port (16). The transceiver switch circuitry is configured to be operable in a reception mode to allow reception signals (31) at the antenna port (18) to be forwarded to the receiver port (17), and in a transmission mode to allow transmission signals (36), having a center frequency with a wavelength λ, at the first transmitter port (15) and the second transmitter port (16) to be forwarded to the antenna port (18) for transmission. The transceiver switch circuitry (30) further comprises a receive arrangement comprising a first λ/4 impedance transformer (32) and a first switch circuitry (33) configured to ground the first λ/4 impedance transformer (32) at the receiver port (17) in the transmission mode; and a transmit arrangement comprising a second λ/4 impedance transformer (26) and a second switch circuitry (35) configured to ground a second side of the second λ/4 impedance transformer (26) in the reception mode.