Weaver Sideband Separation Receiver for Dual-Channel Image Rejection
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Solution Overview
Problem
Existing spectroscopic receivers are not suitable for space missions due to their size, weight, cost, and power consumption, and current health-related and food industry applications require compact, low-power devices capable of dual channel operation for spectral line detection.
Innovation Solution
A compact, low-power, high image rejection sideband separation receiver is developed using the Weaver image reject architecture, incorporating four mixers, two local oscillators, and two low pass filters to simultaneously receive and separate two RF frequencies, achieving high image rejection ratio (IRR) and reducing size, weight, and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional bandpass filter architecture is used to block image band, then image rejection is achieved, but device size and complexity increase
Solution Approach 1:
The patent extracts and removes the image frequency component through quadrature mixing and phase cancellation, eliminating the need for complex bandpass filters. The image rejection is achieved by separating the image band from the signal band through mathematical operations rather than physical filtering.
Solution Approach 2:
The patent replaces mechanical/physical bandpass filtering with electronic signal processing techniques. Instead of using physical filters to block image frequencies, the system uses quadrature mixing and digital/signal processing to achieve image rejection, reducing device complexity.
2Measurement precision
If traditional spectroscopic receivers are used for spectral observation, then measurement capability is sufficient, but size, weight, and power consumption are excessive for space missions
Solution Approach 1:
The patent combines multiple functions (dual-channel reception, image rejection, frequency conversion) into a single integrated Weaver architecture receiver. By merging these functions into one cohesive system rather than separate components, the overall weight is reduced while maintaining spectral observation capabilities.
Solution Approach 2:
The receiver is designed with multi-functionality to perform dual-channel reception and image rejection simultaneously. This universal design allows the same hardware to handle multiple spectral lines and perform multiple operations, reducing the need for separate dedicated components and thereby reducing weight.
3Adaptability or versatility
If dual channel capability is added to receive multiple spectral lines, then measurement capability improves, but device complexity increases
Solution Approach 1:
The patent segments the received signal into two separate channels (upper sideband and lower sideband) through quadrature mixing. This segmentation allows simultaneous processing of multiple spectral lines while using a unified architectural framework, managing complexity through structured division rather than adding independent systems.
Solution Approach 2:
The patent introduces a phase dimension through quadrature mixing (I and Q channels), allowing dual-channel capability to be achieved by exploiting the phase domain. This dimensional approach enables multiple spectral lines to be separated and processed simultaneously without proportionally increasing hardware complexity.
4Volume of moving object
If compact design is implemented to reduce size, then device dimensions are reduced, but power consumption may increase due to integration density
Solution Approach 1:
The patent changes the operating parameters by using low intermediate frequencies (low-IF) in the Weaver architecture. This parameter choice allows for more relaxed filtering requirements and enables the use of energy-efficient circuit topologies, reducing power consumption despite the compact integrated design.
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 proposed receiver achieves a high image rejection ratio of less than about −25 dB, enabling efficient dual channel operation with reduced size, weight, and power consumption, suitable for miniaturized satellites and handheld devices, while maintaining sensitivity comparable to current circuits.
Implementation Method 1
The first two mixers down-convert both signal and image frequencies to intermediate frequencies (IF), and two other mixers further down convert the signals from first IF to a second lower frequency IF
Implementation Method 2
The summation and subtraction, followed by low pass filtering at the output of the second mixer, separate the image and signal frequencies from each other in the upper and lower channels
Implementation Method 3
The local oscillators provide quadrature signals to the mixers that are −π/2 radians out of phase with each other in the upper and lower channels
Data Source
AI summary
A compact, low-power, high image rejection sideband separation receiver is provided. The receiver observes an input radio frequency (RF) signal of multiple spectral lines (spectral observation), then downconverts the signals to intermediate frequency (IF), and then separates the signals to be observed simultaneously in multiple channels. An embodiment is used to observe a signal (G-band) with two spectral lines and utilizes a two stage Weaver architecture to downconvert the signal's frequency, including a combination of mixers in the second stage that achieves the separation of two different channels.