Pin Diode Biasing Circuit Power Reduction

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Solution Overview

Problem

Existing mobile communications devices, such as manpack radios, face high power consumption and heat dissipation issues due to the use of fixed voltage biasing methods for PIN diodes, which can lead to performance problems in multi-band operations.

Innovation Solution

A communication device with a biasing circuit using a switched mode power supply (SMPS) and a feedback circuit to maintain a constant current through PIN diodes, reducing power consumption and heat generation by adjusting the current based on temperature variations and using a high-efficiency step-down SMPS regulator with current sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed voltage biasing is used for PIN diodes, then the device structure is simple, but power consumption is high and heat dissipation increases

Engineering Contradiction:
Improvebiasing circuit structureVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent transforms the fixed voltage biasing approach into a dynamic parameter control system. A microcontroller dynamically adjusts the bias voltage applied to PIN diodes based on real-time temperature sensor readings, changing the electrical parameters adaptively to optimize power consumption while maintaining switching performance across varying operating conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a closed-loop feedback system where temperature sensors continuously monitor the thermal state of PIN diodes and relay this information to a microcontroller. The microcontroller then adjusts the bias voltage accordingly, creating a feedback mechanism that automatically optimizes power consumption based on actual operating temperature, thereby resolving the contradiction between simple structure and power efficiency

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If fixed voltage biasing is used for PIN diodes, then the circuit is simple to implement, but heat dissipation and skin temperature increase

Engineering Contradiction:
Improvecircuit implementationVSAvoidskin temperature
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent enables the biasing circuit to self-regulate based on temperature conditions. Temperature sensors embedded in the system automatically detect thermal states and trigger appropriate bias voltage adjustments without requiring manual intervention or complex external control systems, allowing the circuit to service itself by adapting to thermal conditions

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent transitions from static fixed voltage biasing to dynamic adaptive biasing. The bias voltage becomes a variable parameter that changes in real-time according to temperature conditions, allowing the system to optimize thermal performance by reducing bias voltage when temperatures are high, thereby controlling heat dissipation while maintaining operational simplicity

Inventive Principle:
Principle #15Dynamics

3Device complexity

If fixed voltage biasing is used for PIN diodes, then the design is straightforward, but operational time decreases due to high power consumption

Engineering Contradiction:
Improvebiasing circuit designVSAvoidoperational time
Core Design Contradiction:
Device complexityVSDuration of action of moving object

Solution Approach 1:

The patent implements periodic monitoring and adjustment of bias voltage based on temperature cycles. The microcontroller periodically reads temperature sensor data and adjusts bias voltage in response to thermal conditions, creating a rhythmic pattern of power consumption that reduces overall energy usage during battery operation, thereby extending operational time while keeping the design relatively simple

Inventive Principle:
Principle #19Periodic action

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 solution achieves a power savings of up to 73% compared to prior art devices, increasing operational time and reducing skin temperature, while maintaining reliable PIN diode performance across varying temperatures.

Implementation Method 1

A biasing circuit is provided having a switched mode power supply and a feedback circuit

Methodology Applied
Scientific EffectSwitched mode power supply:

Implementation Method 2

A current sense resistor may be included in the biasing circuit

Methodology Applied
Scientific EffectCurrent sensing: Ohm's Law

Data Source

PatentEP4152626A1RF device with biasing circuit for pin diode and related methods
Publication Date: 2023.03.22 L3HARRIS GLOBAL COMMUNICATIONS INC
  • EP4152626A1 patent drawingFigure 1
  • EP4152626A1 patent drawingFigure 2
  • EP4152626A1 patent drawingFigure 3

AI summary

An RF device may include RF circuitry having a PIN diode configured to switch an RF signal, and a biasing circuit. The biasing circuit may include a controllable power supply having a control input and an current output coupled to the PIN diode to selectively bias the PIN diode into an ON state, and a feedback circuit coupled between the current output and the control input of the controllable power supply to set a current delivered to the PIN diode in the ON state.