RF/Analog

Features

• Distortion-True Design and Test
• 50 Ohm System Environment (when appropriate)
• Global Temperature Setting for Noise Figure Used with RF Amplifiers, Mixers, Splitters, Combiners
• Active Devices: RF Amplifier, Variable Log-Gain-Control Amplifier, Op-Amp Circuits, Mixers
• Passive Devices: Splitters/Combiners, Resistor-Capacitor-Inductor Circuits (Filters), Double-Balanced Diode Ring Mixer
• Diode- and Zener-Diode Circuits

Overview

The RF/Analog Library enhances the SystemVue core libraries with essential models required for system-level RF/Analog design. This library includes models such as fixed- and variable-gain amplifiers, operational amplifier circuits (op-amps), active mixers, double-balanced mixers, power splitters, power combiners, couplers, diode circuits (including Zener diodes), resistor-capacitor circuits, resistor-inductor circuits, low- and high-pass R-C / L-C filters, PLL filters, LC tank and quadrature circuits, coupled-resonator pairs, and more. The RF/Analog Library tokens may be used to create complete transmitter/receiver systems, including the propagated noise figure.

An end-to-end Communication system such as the Binary frequency shift keying (BFSK) system pictured above can be easily simulated using the System View RF/Analog Library.

Typical RF systems that can be designed include AM, FM, analog and digital modulated systems, and spread-spectrum systems. The analog portion of the library allows simulation of PID (proportional, integral, derivative) feedback loops, and various op-amp circuits.

Design Example

The RF / Analog library is used to design a BPSK demodulator using a Costas Loop as shown above. The Costas loop is a special form of a phase-locked loop (PLL) that is often used to demodulate binary PSK.

The top trace is the 50 kHz data used to modulate the
1.0 MHz carrier. The I output is the recovered data. The Q output is the low amplitude signal.

The loop error signal is negative and shows that the
loop lock in time is less than 1 bit time (20 ms).

A Bode plot of a PLL RC filter token.

The RF input signal is applied to two mixers using a two-way zero-degree splitter. The mixer outputs are filtered and limiter-amplified before they combine in a third mixer. The output of the third mixer is connected to a lag-RC loop filter that has an ultimate stopband loss of -12 dB. This error signal is then amplified before it drives the quadrature VCO (FM token). The lowpass LC filters for the data outputs (I and Q sinks) from the first two mixers have been given a lower cutoff frequency than the limiter-amplifier filters.

The PLL RC filter parameter entry window.

Library Tokens

Amplifiers and Mixers

• Amplifier, Fixed
• Amplifier, Traveling Wave Tube (TWTA)
• Amplifier with Variable Gain
• Attenuator, Fixed
• Mixer, Double-Balanced, Active
  
  Mixer, Double-Balanced, Passive

Operational Amplifier Circuits

• Op-amp Buffer circuit (non-inverting)
• Op-amp Hysteresis circuit
• Op-amp Integrate and Dump circuit
• Op-amp Inverter, single input circuit
• Op-amp PID circuit
• Op-amp PLL filter, single input circuit
• Op-amp PLL filter, differential input circuit
• Op-amp Sum of 3 inputs circuit

RC Circuits

• RC Charge Pump circuit
• RC Differentiator circuit
• RC High Pass Filter circuit
• RC Integrate and Dump circuit
• RC Low Pass Filter circuit
• RC PLL Filter circuit

LC Circuits

• LC High Pass Filter circuit
• LC Low Pass Filter circuit
• LC simple Low Pass Filter circuit
• LC Quadrature tank circuit
• LC Capacitive-Coupled Resonator circuit
• LC Tank circuit

Power Combiners and Splitters

• Power Combiner: 2-Way, 180-Degree
• Power Combiner: 2-Way, 0-Degree
• Power Combiner: 3-Way, 0-Degree
• Power Combiner: 4-Way, 0-Degree
• Power Coupler: 2-Way, 0-Degree
• Power Splitter: 2-Way, 180-Degree
• Power Splitter: 2-Way, 0-Degree
• Power Splitter: 3-Way, 0-Degree
• Power Splitter: 4-Way, 0-Degree
• Power Splitter: 2-Way, 90-Degree (Hilbert)

Diode Circuits

• Diode circuit with input to the Anode
• Diode circuit with input to the Cathode
• Diode, Zener circuit with back-to-back pair
• Diode, Zener circuit with input to the Anode
• Diode, Zener circuit with input to the Cathode
• Distortion-True Design and Test
• 50 Ohm System Environment (when appropriate)
• Global Temperature Setting for Noise Figure Used with RF Amplifiers, Mixers, Splitters, Combiners
• Active Devices: RF Amplifier, Variable Log-Gain-Control Amplifier, Op-Amp Circuits, Mixers
• Passive Devices: Splitters/Combiners,
  Resistor-Capacitor-Inductor Circuits (Filters), Double-Balanced
• Diode Ring Mixer
• Diode- and Zener-Diode Circuits

Additional Resources

Read the manual ( 1.1MB)

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