Crest Factor and Scalar-like Measurements with USB Peak Power Sensors
Abstract
Demo: Show how figure of merit crest factor and scalar like measurements can be performed using Boonton 55 series wideband USB Peak Power sensor powered by Real Time Power Processing™.
Measure Crest Factor, Amplifier Gain Compression and Return Loss
Boonton 55 Series USB Peak Power Sensor Demonstration
Demo: Show how figure of merit crest factor and scalar like measurements can be performed using Boonton 55 series wideband USB Peak Power sensor powered by Real Time Power Processing™.
Target Users:
R&D, design, systems engineers and technicians working in commercial and military applications such as 802.11ac, LTE-TDD, LTE-FDD, avionics, RADAR, and medical systems. Engineers measuring RF component and system performance such as amplifier compression and crest factor.
Test Set-up:
About 55 Series Wideband USB Peak Power Sensor & Real Time Power Processing™:
Features:
- Continuous Sample rate: 100 M samples / sec
- Class leading Video Bandwidth: 195 MHz*
- Trace acquisition speed: 100 k sweeps / sec
- Time resolution: 100 ps
- Effective Sample Rate: 10 Gsamples / sec
- Internal RF or External TTL trigger, Master/Slave in/out
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- Statistical Measurements 100 Mpoints / sec
- Ultra-fast rise time: 3ns*
- Real Time Power Processing™: No latency due to buffer processing by host PC
- Synchronized multi-channel measurements
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* 55006 Video bandwidth tested by measuring peak-to-average on a two tone separation signal at +10dbm, frequency set at 1 GHz. Test limit set at 2dB roll off from the nominal 3dB peak-to-average flatness graph.
Measuring Amplifier compression using USB peak power meter:
In our demo set-up we make scalar like measurements to measure gain of an RF amplifier. The Statistical Analysis tool of the 55006 USB Peak Power Sensor creates CCDF graph of the input and output signals. The crest factor can be computed at any percent probability point; so depending on the system requirements and specifications, the user can place the cursor to the desired probability point where the crest factor measurement is to be made. Similarly to measure P1 dB of an amplifier the cursors can be moved along the CCDF curve to the probability point where the difference between input and output crest factor is 1 dB, allowing the designer to determine the P1 dB compression characteristics of the amplifier.
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| Fig.1: Amplifier compression – Input CH1 10.25 dB crest factor – yellow trace, Output CH2 9.0 dB crest factor – red trace. Amplifier compression 1.25 dB |
Fig.2: Tabular format displaying cursor readings, average, peak and peak to average power |
Existing and Comparable Products:
- Boonton's 4500B peak power analyzer. Fully configured the unit has 2 RF and 2 scope input channels. The unit can perform waveform math functions. It can be used with peak power sensors only.
- Boonton's 4541 & 4542 bench top peak power meters. Can be used with peak and average power sensor.
- Multisensor configuration enables simultaneous measurements of forward & reflected power (Return Loss), and amplifier input &output (Gain).