MTTS 2014 Boonton 4500B Demonstration

Abstract

Make forward & reflected power (Return Loss) measurements and measure input & output (Gain) characteristics of a limiter as a DUT by using Boonton 4500B and 4542 RF Peak Power meters.

Instrument of Choice for Characterizing RF Power

Fig.1:  Boonton 4500B and 4542 Peak Power meter connected to the internal Calibrator output of 4500B by using two peak sensors, a bi-directional coupler and a limiter (DUT) to show return loss and I/O characteristics.

About 4500B and 4542 Peak Power Meters:

Key benefits of the Boonton 4500B and 4542 Peak Power meters are processing Repetitive Random Sampling (RRS) techniques for viewing the RF envelope of signal frequencies up to 40 GHz with trigger stability and accuracy.  The 4500B meter has 1 GHz built-in step calibrator, and it also provides a versatile 1 GHz pulse modulated test signal. Both peak meters have a high video bandwidth up to 65 MHz, less than 7 ns rise-time and 70 dB dynamic range (sensor dependent).  Dual channels allow monitoring input and output signal of DUT amplifier. Using CCDF, compression and peaks can be measured.

Significant Features of 4500B:

NOTE: Boonton 4542 meter has similar features except an effective time resolution of 200 pico-sec and fast statistical analysis capability including CCDF with a sampling rate of 50 MSa/sec.

Return loss and output characteristics of a limiter using your own signal:

The built-in calibrator of Boonton 4500B provides a versatile 1 GHz pulse modulated test signal which is used for our demonstration. The internal calibrator of Boonton 4500B peak power analyzer is configured as a programmable pulse signal generator in pulse mode, with the options for modulation rate and duty cycle. Following are a few screenshots of forward vs reflected power measurements (Return Loss) and a comparison of input vs output characteristics of a RF limiter used as the DUT to show the capability of Boonton 4500B peak power meter as a scalar analyzer. While most scalar and network analyzers use swept CW tones to measure gain and return loss, 4500B with peak power sensors and calibrated couplers enable the user to make scalar analyzer measurements.

Forward vs Reflected Power at 0 dBm	Forward vs Reflected Power at 10 dBm	Forward vs Reflected Power at 15 dBm

Fig. 2: Shows how the return loss performance of the limiter diode degrades as it is driven harder. The change of the shape of reflected pulse signal can also be measured and displayed.  

Input vs Output at 5 dBm	Input vs Output at 10 dBm	Input vs Output at 15 dBm

Fig. 3: Shows the change in the pulse waveform characteristics and insertion loss as the limiter diode is driven into saturation. Note how the output of the limiter goes from underdamped to overdamped (ringing).  If the limiter is protecting the input of an amplifier the overshoot in the ringing can potentially damage the amplifier and needs to be measured.

Existing and Comparable Products:

• Replace systems that require crystal detector, a digital oscilloscope, a spectrum analyzer, an average power meter, and assorted connectors & couplings to monitor a single output.
• Dual measurement channels complement the simultaneous measurements of forward & reflected power (Return Loss), and amplifier input & output (Gain)
• Complements Boonton's existing peak power meter family of products and latest 55 series USB Peak Power sensors.