Receiver sensitivity testing is one of the most crucial tests for a prototype or production receiver. This type of test is often performed to either determine the extent of the capability of a new receiver design/communication technology, or as part of a certification test for a receiver designed to meet the requirements of a wireless standard. Without receiver sensitivity testing it would be extremely difficult to determine if a given receiver met the performance requirements of a given standard, or to properly plan out wireless network distribution.
A key element that can be used with receiver sensitivity testing is an RF Attenuator. RF Attenuators are used in receiver sensitivity testing to ensure that the power delivered to the receiver-under-test (RUT) is set at the desired low power specified for the test, or as low as is needed to test the extent of the sensitivity of a receiver. Receiver sensitivity testing can be performed with Fixed Attenuators while using a frequency or signal source with variable power output. However, it is more common to use a frequency generator/signal generator within the device’s most linear and low noise floor (NF) power range, which may be somewhat limited. This is why it is more common to use Variable Attenuators for receiver sensitivity testing.
There are a variety of Variable Attenuators that may be used for this application: Analog/Continuously Variable Attenuators, Step Attenuators, Voltage Variable Attenuators, and Programmable Attenuators. If there is very little complexity to the power range for testing and manual adjustment or adjustment based on analog feedback is necessary, Continuously Variable, Voltage Variable, or Step Attenuators may be applicable. In most test applications it may be desirable to instead use a quality Programmable Attenuator with adequate range and specifications that can meet the majority of the requirements for a test laboratory or automated test installation.
Using a Programmable Attenuator always for the calibration plane of the receiver sensitivity test to be brought to the input of the RUT, while still having a flexible range of input signal power. This enhances the accuracy of receiver sensitivity testing and can improve the dynamic range of the test as well.
Depending on the available or preferred control technologies, any of the common types of Programmable Attenuators are suitable for this type of testing: CMOS Controlled Programmable Attenuators, Relay Controlled Programmable Attenuators, TTL Controlled Programmable Attenuators, USB Controlled Programmable Attenuators.