High-Power Amplifier Measurements with the PNA

The following is a block diagram of all models of the PNA-X Opt 423. However, all of the models listed below have the same or fewer components.  

The configuration displayed here is used to make high power amplifier measurements using a preamplifier at the rear panel. The preamplifier can then be switched (SW1) as needed using the RF Configurator.

Damage Levels

Model

Bridges/Combiners

Couplers

Bias-tees

N5241A, N5242A, N5249A

+33 dBm

+43 dBm

+30 dBm

N5244A, N5245A

+27 dBm

+43 dBm

+30 dBm

N5247A

+27 dBm

+30 dBm

+30 dBm

N5221A, N5222A

N/A

+43 dBm

+30 dBm

N5224A, N5225A

N/A

+43 dBm

+30 dBm

N5227A

N/A

+30 dBm

+30 dBm

ALL Switches: Damage level = 1 Watt (+30 dBm) while switching.

ALL Step Attenuators: Damage level = 1 Watt (+30 dBm) while switching.

Notes

At J11 (rear-panel), max power is 4 dB to 11 dB higher than Source 1 Out at front panel jumper due to loss of the coupler thru arms, bias-tees, and cables.

At J10 max power +33 dBm, which is the damage level of the bridge. With +30 dBm into J10, there will be about +15 dBm at R1, assuming 15 dB coupling factor for the R1 bridge. +15 dBm is the damage level of that receiver. Therefore, it may be necessary to add attenuation in place of the R1 loop, not only to protect the receiver, but to bring it out of compression. The 0.1 dB compression level spec for the R1 receiver is between -3 and -18 dBm, depending on the frequency and option configuration.

At Test Port 2 (DUT output): With the bias-tees (orange), only +30 dBm is allowed into the test port. With Opt H85  (bias-tees removed), +43 dBm is allowed. Add appropriate attenuation to not damage other components.

About the PNA-X  Option H85

A modified version of the standard PNA-X, the option H85 is designed to permit insertion of high power amplifiers and other signal conditioning equipment to allow high power network measurements at RF levels up to 20 Watts (+43 dBm) from 10 MHz to 26.5 GHz. The Option H85 modification supplies extended power range attenuators without bias tees. This is similar to the PNA-X -219 (add extended power range and bias-tees to 2-Port analyzer) or PNA-X -419 (add extended power range and bias-tees to 4-Port analyzer) but deletes the bias tees from the test set.

See Also