Embedded-Attenuator SPDT Switches for Lower RF Insertion Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Single-pole double-throw (SPDT) switches in RF applications experience higher insertion loss and occupy a large area due to the inclusion of inductors, which affects their performance and efficiency.
Innovation Solution
Incorporating embedded attenuator circuits within the SPDT switches, comprising series and shunt switching elements connected in parallel, allowing for selective attenuation by controlling the states of these elements to directly connect the attenuator circuits to the common input, thereby reducing insertion loss and area consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inductors are included in SPDT switches for RF applications, then switching functionality is achieved, but insertion loss increases and area consumption increases
Solution Approach 1:
The patent combines the SPDT switch functionality with attenuator functionality into a single integrated circuit. The attenuator circuit is merged with the switch structure, allowing the same components to perform both switching and attenuation functions, thereby reducing the need for separate inductor-based attenuator circuits and reducing overall insertion loss
Solution Approach 2:
The switch circuit is designed to perform multiple functions: it acts as both an SPDT switch and an attenuator. By making the switch circuit universal, it can operate in different modes (switching mode and attenuation mode) depending on the application requirements, eliminating the need for separate dedicated inductor-based attenuator circuits
2Reliability
If inductors are included in SPDT switches for RF applications, then switching functionality is achieved, but area consumption increases
Solution Approach 1:
The patent merges the attenuator functionality into the existing switch circuit structure. By integrating the attenuator circuit with the switch, the design eliminates the need for separate inductor-based attenuator circuits, thereby reducing the overall area consumption on the die while maintaining both switching and attenuation functions
Solution Approach 2:
The switch circuit is designed to perform multiple functions including switching and attenuation. This multi-functionality allows the same circuit components to serve multiple purposes, reducing the total component count and area required compared to having separate dedicated switch and attenuator circuits
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A single pole double throw (SPDT) switch with embedded attenuators includes a transmitter attenuator circuit directly connected to a common input of the SPDT switch, and a receiver attenuator circuit directly connected to the common input of the SPDT switch. Switches in the transmitter attenuator circuit and in the receiver attenuator circuit are selectively or individually set to an open state or to a closed state to directly connect the transmitter attenuator circuit or the receiver attenuator circuit to the common input. The selective setting of the states of the switches also determines a given amount of attenuation for the transmitter attenuator circuit or the receiver attenuator circuit.