# SPST

Single pole single throw switch

• Library:
• RF Blockset / Circuit Envelope / Junctions

## Description

The SPST block models a single pole single throw switch. This block supports both reflective and absorptive switches. The control signal is a Simulink® signal connected to the `Vctl` port of the block. The control signal specifies when the output port, `Out`, transmits the input signal at the input port, `In`.

## Ports

### Input

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Simulink control signal, specified as a scalar.

Data Types: `double`

## Parameters

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Threshold voltage of the switch, specified as a positive scalar in volts.

Characterization of the switch, specified as `Resistance` or `Insertion loss`.

On resistance value of the switch, specified as a positive scalar in ohms. On resistance is available when you set Characterization to `Resistance`.

Off resistance value of the switch, specified as a positive scalar in ohms. Off resistance is available when you set Characterization to `Resistance`.

Insertion loss value of the switch, specified as a positive scalar in decibels. Insertion loss (dB) is available when you set Characterization to ```Insertion loss```.

Isolation value of the switch, specified as a scalar in decibels. Isolation (dB) is available when you set Characterization to ```Insertion loss```.

Loading type of the switch, specified as `Reflective` or `Absorptive`.

Port terminations that match the impedance conditions of the `SPDT` switch, specified as a scalar in ohms or a vector of size 1-by-2 with each element unit in ohms. If the value is a scalar, then the input port and the output port impedances are the same. If the value is a vector, the first value is the matching required at the inport of the block and the second values is the matching required at the output port.

Note

Port terminations is available when you set the `SPST` switch Characterization to `Insertion loss` or when you set Loading type to `Absorptive`.

Select this parameter to internally ground and hide the reference terminals. To expose the reference terminals, clear this parameter. By exposing these terminal, you can connect them to other parts of your model.

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