Frequency Converter LO Tuning for Leakage Filter Relief
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Solution Overview
Problem
Conventional frequency converters require high performance filter circuits to suppress leakage signals, which increases device size and cost due to smaller frequency intervals between local oscillation signals and side bands.
Innovation Solution
Increasing the frequency interval between local oscillation signals and side bands by adjusting the settings of ωLO and IFtx to relax the performance requirements of filter circuits, allowing for reduced size and cost in wireless devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a filter circuit is used to suppress leakage signal, then leakage signal suppression is improved, but device size and cost increase due to high performance requirements
Solution Approach 1:
The patent changes the frequency parameter by adjusting the local oscillation frequency ωLO to create a larger frequency interval between the local oscillation signal and the side bands. This parameter change allows the use of lower performance filter circuits with smaller size while still achieving effective leakage signal suppression.
2Object-affected harmful factors
If a high performance filter circuit is used to suppress leakage signal, then leakage signal suppression is improved, but device cost increases
Solution Approach 1:
By adjusting the local oscillation frequency ωLO to maximize the frequency interval between the local oscillation signal and side bands, the patent enables the use of lower performance, lower cost filter circuits that still meet the leakage signal suppression requirements.
3Productivity
If frequency interval between local oscillation signal and side bands is small, then frequency conversion efficiency is improved, but filter circuit performance requirements increase
Solution Approach 1:
The patent optimizes the local oscillation frequency ωLO to achieve an optimal balance where the frequency interval is sufficiently large to relax filter circuit performance requirements, while maintaining acceptable frequency conversion efficiency through proper mixer 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 increased frequency interval simplifies the filter circuit requirements, leading to smaller and less expensive wireless devices with improved suppression of leakage signals.
Implementation Method 1
a frequency converter converts a signal with an intermediate frequency of ωIF to at least one of a wireless signal with a frequency of ωLO-ωIF (hereinafter referred to as LSB: Lower Side Band) and a wireless signal with a frequency of ωLO+ωIF (hereinafter referred to as USB: Upper Side Band). When this conversion is performed, a local oscillation signal with a frequency of ωLO is used.
Data Source
Figure 1~2
AI summary
A frequency converter up-converts a transmission signal in an intermediate frequency band into a signal in a wireless frequency band as a USB or an LSB of a local oscillation signal using the local oscillation signal. When PMhigh-1/2×IFwid ≤ RFtx ≤ PMhigh-1/2×CHwid, the frequency converter is configured to satisfy coLO = PMhigh-1/2×IFwid-IFcent and IFtx = RFtx-ωLO. Alternatively, when PMlow+1/2×IFwid ≥ RFtx ≥ PMlow+1/2×CHwid, the frequency converter is configured to satisfy ωLO = PMlow+1/2×IFwid+IFcent and IFtx = ωLO-RFtx.