Satellite LNB Frequency Translation and Switch Matrix
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing satellite receiver systems face challenges in providing simultaneous and independent tuning to multiple satellite signals due to increased complexity and potential signal quality degradation from secondary frequency conversion, which can lead to service interruptions during switch-over.
Innovation Solution
The system achieves simultaneous and independent reception by performing frequency conversion from RF to IF with a single downconversion step, reducing complexity and preserving signal quality, and uses a switch matrix with constant impedance switching to minimize transient effects during switch-over.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If secondary frequency conversion is used to enable independent tuning to multiple satellite signals, then the capability to receive channels from any polarization of any satellite is improved, but the system complexity increases and signal quality may degrade
Solution Approach 1:
The patent extracts and eliminates the secondary frequency conversion stage from the signal path. By removing this redundant conversion step, the system achieves the same multi-channel reception capability with reduced complexity. The LNB is designed to output signals that can be directly switched and distributed without requiring additional frequency translation, thereby simplifying the overall architecture while maintaining the ability to receive channels from any polarization of any satellite.
Solution Approach 2:
The patent merges the frequency conversion function into a single stage within the LNB, combining what were previously separate conversion operations. The LNB performs frequency downconversion to a unified intermediate frequency band, and the subsequent switching network handles signal distribution. This consolidation eliminates the need for separate secondary conversion circuits at each output, reducing system complexity while preserving full adaptability for receiving channels from multiple satellites and polarizations.
2Adaptability or versatility
If secondary frequency conversion is implemented to provide simultaneous independent reception, then multiple tuners can independently tune to any channel, but service interruptions may occur during switch-over
Solution Approach 1:
The patent implements preliminary frequency conversion within the LNB, converting all satellite signals to a common intermediate frequency band before distribution. This preliminary action ensures that all signals are already in the correct frequency range for the tuners, eliminating the need for secondary conversion during operation. The switching network then simply routes pre-converted signals, avoiding service interruptions that would otherwise occur during dynamic frequency translation at the point of use.
3Adaptability or versatility
If band translation switch technology is used to resolve independent tuning problems, then channel reception from multiple satellites is enabled, but the system requires complex switching and frequency conversion circuitry
Solution Approach 1:
The patent changes the frequency parameter of all satellite signals to a unified intermediate frequency band within the LNB. By converting all inputs to the same frequency range, the subsequent switching network operates with simplified, frequency-matched signals. This parameter transformation eliminates the need for complex band translation switching, as the switching circuitry now handles signals that are already in compatible frequency bands, reducing overall system complexity while maintaining multi-satellite reception capability.
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 approach simplifies the satellite receiver system, reduces costs, and eliminates secondary frequency conversion, thereby enhancing signal integrity and preventing service interruptions by controlling switch-over transitions.
Implementation Method 1
The converter block 10, performing frequency downconversion, contains local oscillators LO1 14 and LO2 12 typically of the dielectric-resonator oscillator (DRO) type, mixers, and post-mixer amplifiers
Implementation Method 2
The L and H frequency bands are then summed together in a separate combiner 16 in each arm, forming a composite signal having both frequency bands, 'L+H'
Data Source
AI summary
An outdoor satellite receiving unit (ODU) receives several independent satellite signals, selects two signals with a switch matrix, downconverts the two signals to a bandstacked signal with a high and a low band signal, and outputs the bandstacked signal on the same cable to receiver units. Several satellite signals can be selected in groups of two or more and output to independent receiver units. Signal selecting is performed at the received radio frequency (RF) and bandstacking is performed with a single downconversion step to an intermediate frequency (IF). Channel stacking on the same cable of more than two channels from several satellites can be achieved by using frequency agile downconverters and bandpass filters prior to combining at the IF output. A slow transitioning switch minimizes signal disturbances when switching and maintains input impedance at a constant value.