Multi-Input Mixer Circuit Without RF Switch Attenuation
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Solution Overview
Problem
Conventional UWB receiver circuits require multiple mixers and switches, leading to increased circuit area and signal attenuation due to parasitic resistances and capacitances, resulting in unsatisfactory signal quality.
Innovation Solution
A multi-input mixer comprising a differential pair circuit, transistors, and a selecting circuit that allows multiple RF signals to be mixed using a single mixer device, eliminating the need for additional mixers and switches by controlling the mixing process with an enable signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple mixers are used to handle multiple RF signals, then signal mixing capability is improved, but circuit area increases
Solution Approach 1:
The patent combines multiple mixer functions into a single multi-input mixer device. Multiple RF signals are fed into one mixer through a differential pair circuit structure, where multiple transistor pairs process different RF inputs simultaneously. This merging approach maintains the signal mixing capability for multiple RF signals while reducing the overall circuit area by eliminating the need for separate mixer circuits for each RF signal.
Solution Approach 2:
The mixer device is designed with universal functionality to handle multiple RF signals through a single device. The differential pair circuit configuration allows the same mixer structure to process multiple RF inputs by using multiple transistor pairs, each capable of mixing a specific RF signal with the local oscillator signal. This multi-functional design enables one mixer to perform the work of multiple traditional mixers.
2Adaptability or versatility
If switches are used to control parallel connection of capacitors to filtering inductors, then filtering frequency response adaptability is improved, but signal attenuation increases due to parasitic resistances
Solution Approach 1:
The patent extracts and eliminates the switches from the signal path that were previously used to control the parallel connection of capacitors to filtering inductors. By removing these switches, the parasitic resistances and capacitances that caused signal attenuation are eliminated. The filtering frequency response adaptability is maintained through alternative means that do not require switching elements in the signal path.
Solution Approach 2:
The filtering frequency response is predetermined and configured without requiring dynamic switching during operation. The circuit is designed with fixed filtering characteristics that are optimized for the intended application, eliminating the need for switches to reconfigure the filtering network. This preliminary configuration approach maintains adaptability while avoiding the signal attenuation problems associated with switch parasitics.
3Adaptability or versatility
If switches are used to control series connection of inductors to filtering inductors, then filtering frequency response adaptability is improved, but frequency response drift occurs due to parasitic capacitances
Solution Approach 1:
The patent removes the switches from the circuit configuration that was used to control the series connection of inductors to filtering inductors. By extracting these switching elements, the parasitic capacitances that caused frequency response drift are eliminated. The filtering frequency response accuracy is maintained through the redesigned circuit topology that does not rely on dynamic switching for frequency selection.
4Adaptability or versatility
If additional low-noise amplifiers are added to increase bandwidth, then bandwidth coverage is improved, but device complexity increases
Solution Approach 1:
The patent merges the functionality of multiple low-noise amplifiers into a single multi-input mixer device. The differential pair circuit structure allows multiple RF signals to be processed simultaneously within one device, eliminating the need for separate amplifier stages for each frequency band. This combining approach maintains comprehensive bandwidth coverage while reducing the overall device complexity by integrating multiple functions into a unified circuit architecture.
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 reduces circuit area size, avoids signal attenuation, and maintains accurate filtering frequency responses, enhancing signal quality in UWB communications.
Implementation Method 1
Each of the plurality of first transistors determines to mix the respective radio frequency input signal with the differential input signal to generate a first differential output signal
Data Source
AI summary
A mixer device includes a differential circuit, a transconductance circuit, and a selecting circuit. The differential circuit receives a differential input signal and generates a differential output signal. The transconductance circuit is coupled to the differential circuit, receives a plurality of radio frequency input signals, and determines to mix at least one of the radio frequency input signals with the differential input signal according to an enable signal. The selecting circuit receives a control signal and generates the enable signal according to the control signal.