WLAN Transceiver Integrated Switches and Matching Networks

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Solution Overview

Problem

Conventional wireless radios face issues with loading effects when the transmit and receive paths are tied together, leading to degradation of output power and noise figure, and require external transmit/receive (T/R) switches that incur additional loss and cost.

Innovation Solution

An integrated circuit-based radio transceiver with series and shunt switches, along with external matching networks, allows the transmit and receive paths to be tied together without an external T/R switch, minimizing loading effects and using a shared balun to convert differential signals to single-ended signals for antenna interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If external T/R switch is used to prevent loading effects, then transmit path output match and receive path input match are improved, but additional loss and cost are incurred

Engineering Contradiction:

Improvetransmit path output match and receive path input matchVSAvoidadditional loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent merges the T/R switch functionality with the matching networks by integrating them into a single circuit structure. The series switch is combined with the transmit path matching network, and the shunt switch is combined with the receive path matching network, eliminating the need for separate external T/R switches and reducing additional losses

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The matching networks are designed to serve dual functions: impedance matching for the respective paths and T/R switching functionality. The series switch in the transmit path matching network and shunt switch in the receive path matching network work together to provide both matching and switching operations, reducing component count and losses

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If external T/R switch is used to prevent loading effects, then transmit path output match and receive path input match are improved, but board space and cost increase

Engineering Contradiction:

Improvetransmit path output match and receive path input matchVSAvoidboard space

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent combines multiple functions (impedance matching and T/R switching) into integrated circuit structures, eliminating the need for separate external T/R switch components and reducing the overall board space required for the transceiver design

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If fully integrated T/R switch is used, then external switch components are eliminated, but on-chip matching adds additional loss

Engineering Contradiction:

Improveexternal switch componentsVSAvoidon-chip matching loss

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent segments the matching networks into external components rather than integrating them fully on-chip. The series switch and shunt switch are implemented as discrete external components that work with the matching networks to provide T/R functionality while avoiding the losses associated with on-chip matching structures

Inventive Principle:

Principle #1Segmentation

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 maintains output power and noise figure performance by minimizing loading between paths and eliminates the need for external T/R switches, reducing losses and costs while providing flexibility in component selection.

Implementation Method 1

a shared balun for converting differential signals from the plurality of external matching networks to single ended signals

Methodology Applied

Scientific EffectElectromagnetic transformation: Electromagnetic Induction

Data Source

PatentUS9397720B2Method and system for integrating transmit switch functionality in a WLAN radio transceiver

Publication Date: 2016.07.19 MEDIATEK INC

AI summary

A radio transceiver is disclosed. The transceiver comprises an integrated circuit. The integrated circuit comprises a transmit path; a first switch coupled in series with the output of the transmit path; a receive path; and a second switch coupled as a shunt with the input of the receive path. The transceiver further comprises a plurality of external matching networks coupled to the transmit and receive paths of the integrated circuit to ensure minimal loading from one path to the other. The transceiver also comprises a shared balun for converting differential signals from the plurality of external matching networks to single ended signals; and an antenna to interface with the single ended signals. A method and system in accordance with an embodiment enables tying together the transmit path and the receive paths of a radio transceiver without the need for an external T/R switch. A method and system in accordance with an embodiment minimizes the loading effects between the transmit path and the receive path such that output power and NF noise figure are not degraded after tying the transmit path and the receive path together.