Switchable VSAT Modem Reference Signal Path for Single-IFL Mode Switching
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Solution Overview
Problem
Current VSAT systems require two separate modems for linear and saturated modes, necessitating two interfacility links (IFLs) for installation and configuration, which is costly and inefficient.
Innovation Solution
A switchable satellite modem that can operate in both linear and saturated modes using a single IFL, employing a synthesizer modulator chip, electronic switch, and prescaler to generate and transmit frequencies suitable for both BUC and PLL based upconverters, allowing dynamic switching between modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two separate modems are used for linear and saturated modes, then each modem can be optimized for its specific mode, but the device complexity and installation cost increase due to requiring two IFLs
Solution Approach 1:
The patent implements a single VSAT modem capable of operating in both linear and saturated modes by incorporating a switchable power amplifier that can function in either mode. The modem includes a controller that configures the power amplifier based on the selected transmission mode, eliminating the need for separate modems for each mode while maintaining optimized performance for both operational states
Solution Approach 2:
The patent combines the functionality of two separate modems (linear mode modem and saturated mode modem) into a single unified VSAT modem. The power amplifier is designed to handle both linear and saturated operations, and the control system integrates mode selection and switching logic, thereby reducing the total number of required modems and interfacility links from two to one
2Adaptability or versatility
If two separate modems with two IFLs are installed, then linear and saturated modes are supported, but installation and configuration complexity increases
Solution Approach 1:
The single VSAT modem incorporates a controller that can configure the power amplifier for different transmission modes (linear or saturated). The system allows mode selection through control signals that adjust the power amplifier's operating characteristics, enabling versatile support for multiple transmission modes while maintaining a unified installation with a single IFL
Solution Approach 2:
The power amplifier is designed with dynamic reconfigurability, allowing it to switch between linear and saturated operating modes based on control signals from the modem's controller. This dynamic switching capability enables the system to adapt to different transmission requirements without requiring separate hardware installations for each mode
3Device complexity
If a single modem supports both modes, then hardware complexity is reduced, but the difficulty of detecting and measuring the optimal mode increases
Solution Approach 1:
The controller in the VSAT modem monitors system parameters and transmission conditions to determine the optimal operating mode. Based on feedback from the transmission performance and system state, the controller automatically configures the power amplifier in either linear or saturated mode, eliminating the need for manual mode detection and simplifying the measurement and selection process
Data Source
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AI summary
A modem to interface with a constant envelope saturated and/or linear radio, the modem including: a synthesizer modulator configured to generate a reference signal; a prescaler configured to reduce the reference signal to a lower frequency signal; a switch configured to enable the prescaler; and an output configured to output the reference signal when the prescaler is disabled, and configured to output the lower frequency signal as the reference signal when the prescaler is enabled.