HP manual HP 8753E System Operation, Built-In Synthesized Source

HP 8753E System Operation

Network analyzers measure the reflection and transmission characteristics of devices and networks. A network analyzer test system consists of the following:

nsource

nsignal-separation devices

nreceiver

ndisplay

The analyzer applies a signal that is transmitted through the test device, or reflected from its input, and then compares it with the incident signal generated by the swept RF source. The signals are then applied to a receiver for measurement, signal processing, and display.

The HP 8753E vector network analyzer integrates a high resolution synthesized RF source, test set, and a dual channel three-input receiver to measure and display magnitude, phase, and group delay of transmitted and reflected power. With Option 010, the analyzer has the additional capability of transforming measured data from the frequency domain to the time domain. other options are explained in Chapter 1, “Analyzer Description and Options.” Figure 6-l is a simplified block diagram of the network analyzer system. A detailed block diagram of the analyzer is provided in the HP 87533iVetwork AruzZgwr Semrice ouide together with a theory of system operation.

P H A S E L O C K

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Figure 6-1. Simpliried Block Diagram of the Network Analyzer System

The Built-In Synthesized Source

The analyzer’s built-in synthesized source produces a swept RF signal or CW (continuous wave) signal in the range of 30 kHz to 3.0 GHz. The HP 8753E Option 006 is able to generate signals up to 6 GHz. The RF output power is leveled by an internal ALC (automatic leveling control) circuit. To achieve frequency accuracy and phase measuring capability, the analyzer is phase locked to a highly stable crystal oscillator. For this purpose, a portion of the transmitted signal is routed to the R channel input of the receiver, where it is sampled by the phase detection loop and fed back to the source. Some portion of the RF source signal must always be sent to the R channel input. The level must be between 0 dB and -35 dDm.

The Source Step Attenuator

The step attenuator contained in the source is used to adjust the power level to the test device without changing the level of the incident power in the reference path.

5-2 Application and Operation Concepts