RF Power Sensor Feedback Circuit for Wide Dynamic Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing RF power sensors face limitations such as limited dynamic range, poor power supply rejection, and contamination of power supply and ground by nonlinear currents, leading to inaccurate measurements and increased power consumption due to iterative range setting processes.
Innovation Solution
The RF power sensor design incorporates a power sensor transistor, a current mirror, a feedback circuit, and additional features like a load slope control circuit and RF loop to provide improved power supply rejection, high sensitivity, and a large dynamic range, preventing nonlinear currents from contaminating the power supply and ground.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional RF power sensor designs are used, then the device can detect RF signal power, but the dynamic range is limited and requires iterative range setting processes
Solution Approach 1:
The patent implements a feedback circuit that dynamically adjusts the bias current based on the detected RF signal power level. The circuit automatically transitions between different measurement ranges without requiring manual intervention, making the sensor adaptable to a wide dynamic range while eliminating the need for iterative range setting processes
Solution Approach 2:
The feedback circuit continuously monitors the output of the power sensor transistor and adjusts the bias current accordingly. When the output approaches saturation, the feedback circuit reduces the bias current to extend the measurement range, and when the output is below the detection threshold, it increases the bias current to improve sensitivity, thereby achieving automatic adaptive range setting
2Reliability
If conventional RF power sensor designs are used, then the device can operate with simple circuitry, but power supply rejection is poor and nonlinear currents contaminate the power supply and ground
Solution Approach 1:
The patent extracts the nonlinear current component from the main signal path by using a dedicated feedback circuit that senses and compensates for these harmful currents. The feedback circuit isolates the power supply and ground from the nonlinear current contamination generated by the power sensor transistor, preventing it from affecting other circuit components
Solution Approach 2:
The feedback circuit acts as an intermediary between the power sensor transistor and the power supply/ground. It introduces a compensating current that counteracts the nonlinear currents, thereby improving power supply rejection ratio and preventing contamination of the power supply and ground networks
3Measurement precision
If conventional RF power sensor designs are used, then the device can be manufactured with standard components, but measurement accuracy is compromised due to limited dynamic range and power supply issues
Solution Approach 1:
The feedback circuit continuously monitors the output voltage of the power sensor transistor and dynamically adjusts the bias current to keep the operating point within the optimal linear region. This ensures high measurement accuracy across a wide dynamic range by preventing saturation and improving the detector's linearity, while the automatic adjustment eliminates the need for complex manual calibration procedures
Data Source
AI summary
Aspects of the disclosure relate to devices, wireless communication apparatuses, methods, and circuitry for a RF power sensor. One aspect is an apparatus including a power sensor transistor configured to receive a radio frequency (RF) input signal and to generate an output indicative of a power of the RF input signal. The apparatus further includes a current source configured to generate a bias current. Also, the apparatus includes a current mirror, which is formed by the power sensor transistor and a second transistor, configured to provide the bias current to the power sensor transistor. The apparatus further includes a feedback circuit, which is coupled to the power sensor transistor and the second transistor, configured to control a drain current of the second transistor with respect to the bias current.