RF Blockset 2.5

Data File for Amplifier

This model illustrates how to use the General Amplifier block to model an amplifier whose parameters are specified in a data file. The data file default.s2d contains the S-parameters of an amplifier at frequencies ranging from 1 GHz to 2.9 GHz. It also contains power-dependent S21 data at 2.1 GHz.

Contents

Demo Model

Fig. 1 Physical RF amplifier demo model:

Simulation Results

The following figure shows the input and output spectrums of the nonlinear amplifier over the frequency range from 1.85 GHz (-0.25 GHz) to 2.35 GHz (0.250 GHz). This is the range of frequencies the complex baseband-equivalent model uses to simulate the amplifier. For more information about complex baseband-equivalent modeling, see Creating a Complex Baseband-Equivalent Model section of the doc.

Fig. 2 Baseband-Equivalent Spectrum:

The complex baseband-equivalent model is a frequency-shifted model of the passband frequency response you specify for the amplifier. You can relabel the X-axis of the FFT Scope to display the passband frequency response by entering the center frequency (from the Input Port block) into the "Frequency display offset (Hz):" parameter in the FFT Scope block. In this case the implicit units are MHz, so enter "2.1e9" to label the center frequency as 2.1 GHz.

Fig. 3 Specification of the X-axis Relabel:

Fig. 4 Passband Spectrum:

To see the frequency response centered at another RF frequency, change the Center frequency parameter in the Input Port block.