1-Tone Nonlinear Simulations > Spectrum, Gain, Harmonic Distortion at X dB Gain Compression vs. Freq.

Description

This is similar to the HB1ToneFswp simulation setup, and it simulates the spectrum, output power, power gain, harmonic distortion, and group delay of a device or amplifier at the X dB power gain compression point, versus frequency. You can specify the amount of gain compression, X, in dB. The simulator then increases the available source power to the device until the power gain has been reduced by X dB, relative to its small-signal value. This simulation is repeated at each input frequency in a range you specify. A sample power amplifier is provided. You must replace this amplifier with your own device or amplifier, and modify the biases, as needed.

Needed to Use Schematic

A device or an amplifier using nonlinear model(s)

Main Schematic Settings

Range of input frequencies, the amount of power gain compression, in dB, and the source and load impedances at the fundamental and harmonic frequencies

Data Display Output

All at the X dB gain compression point, and versus input frequency:

• Output spectrum and voltage waveform at a frequency selected by moving a marker
• Fundamental output power
• Transducer power gain (power delivered to the load minus power available from the source)
• Harmonic distortion up to the 5th, in dBc
• Group Delay

Schematic Name

HB1ToneGCompFswp

Data Display Name

HB1ToneGCompFswp.dds

Note

When simulating a device, setting the source and load impedances at the fundamental and harmonic frequencies might be useful. However, when simulating an amplifier that already has source and load impedance matching networks, leaving all these impedances at 50 ohms might be suitable. This gain compression simulation might not work well on amplifiers that have low gain at low signal level (like Class B amplifiers) or ones that have excessive gain expansion. In this case, use one of the simulation setups that explicitly sweeps power.