Application: RF & Microwave

AN208: Microwave Receiver Linearity Verification

The linearity of an RF or microwave receiver is typically measured at its intermediate frequency. Nonlinearities at high signal levels due to mixer compression, and at low levels due to noise, are then specified as maximum error figures. This application note shows how linearity can be measured over a frequency range of 100kHz to 40GHz…
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AN212: Constructing a 100mW RF Power Reference

Conventional calibrations typically take place in the 1mW to 10mW range. This range can be extended downwards for highly sensitive diode sensors by means of a calibrated attenuator. Raising the calibration level above 10mW is more of a challenge. This application note describes a basic technique for generating an accurate 100 mW power source.
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AN213: Return Loss and VSWR Measurement Methods

Both VSWR and Return Loss are a measure of the divergence of a microwave device from a perfect impedance match. They are mathematically interchangeable and result from scalar measurements. This app note describes the use of a TEGAM System IIA Power Sensor Calibration System for VSWR and Return Loss measurements.
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AN216: Limitations of AM Leveling Loops

Characterizing RF power sensors is commonly done using a direct comparison system which employs a resistive RF power splitter with a power standard connected to a power meter. The microwave source is often maintained at a stable level with an external AM input. This application note discusses the limitations to this technique and some alternatives.
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AN220: Measuring RF Power Sensor Nonlinearity

RF power sensor linearity is a commonly misunderstood topic. To obtain the most accurate power measurements, though, you need to understand what linearity is, the sources of nonlinearity, and how to measure the linearity of your RF power sensors.
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AN221: Coaxial Flow Calorimeter

How Accurate Are Your RF Measurements? Accurate power measurements on RF signals require a thorough knowledge of the varying nature of the signals under test. We have obtained very good results with this system, improving the uncertainty of a 100W, 1GHz flow calorimeter to 0.43% of full scale. Using this system, through-line wattmeters can be…
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