Tegam

RF & MICROWAVE

1. 1. 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.

2. 2. 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.

3. Calculating a Calibration Factor

Technicians and engineers use calibration factors when making measurements; but where do these calibration factors really come from?

4. 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.

5. Measuring Temperature Compensating Thermistors with the TEGAM Model 1830A RF Power Meter

This document explains the theory behind measuring power with a dual bridge Power Meter such as the Agilent 432A and shows the reader how to simplify the measurement with the TEGAM 1830A RF Power Meter.

6. 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 using a precision power meter and RF power standards.

7. Output Standing Wave Ratio (SWR) Test Using the TEGAM 1830A RF Power Meter

The TEGAM Model 1830A RF Power Meter coupled with a thermistor power sensor (also known as a thermistor mount) can accurately measure the SWR of a 50 MHz reference. By utilizing a unique function that most modern power meters do not offer; the 1830A allows the user to change the value of the thermistor mounts terminating resistance.

8. Using Agilent Temperature Compensated Thermistor Mounts With TEGAM Type IV Power Meters

There are many different types of temperature compensated thermistor mounts such as the Agilent 478A and 8478A. Type IV power meters such as Tegam’ s 1806A, 1804, and 1806 can be used to monitor these thermistor mounts.

SIGNAL GENERATION & AMPLIFICATION

9. 4040A Stand Alone Instrumentation Amplifier

A differential instrumentation amplifier is an essential and versatile tool for use in various tests and experiments. For convenience, TEGAM offers a complete package that includes a 4040A instrumentation amplifier, LabVIEW control software and a PXI-1033 chassis.

10. Considerations for Selecting a Power Amplifier

This Application Note is intended to assist people who are not power amplifier experts to understand the basic parameters such as Gain, Bandwidth (BW), Slew Rate (SR), Total Harmonic Distortion (THD), Input Impedance and Current Limit necessary to properly select an amplifier for use in testing and experimentation.