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Anritsu ME7840A manual Chapter Preamplifier Operations, Use, External, Preamplifiers, Alternative

Models: ME7840A

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Chapter 7

Preamplifier Operations

7-1

7-2

INTRODUCTION

This chapter describes the use of external preamplifiers to boost signal

 

power at the input of an test amplifier.

USE OF

External preamplifiers can be used to boost signal level at the input of

EXTERNAL

the Amplifier Under Test (AUT). The maximum power per tone at the

PREAMPLIFIERS

AUT input without any external preamplifier is +5 dBm.Block diagrams

 

showing this feature are contained in Figures 7-1and 7-2.

 

As shown in Chapter 1, Figures 1-2and 1-3,a single preamplifier can be

 

used after the combiner and before the bi-directional input coupler. How-

 

ever the nonlinearity of this preamplifier may adversely affect the linear-

 

ity measurements of the AUT, unless it is far below the AUT.

 

If an individual preamplifier for each tone is used at the input to the

 

combiner, then this problem is avoided, but two other issues must be ad-

 

dressed:

 

￿ Driving the DRA Scorpion channels a1 and b1 into compression

 

￿ Possibility of damage to the combiner

 

The first issue is avoided by using an attenuator at the input of channels

 

a1 and b1. The value of this attenuator should be selected noting that the

 

maximum operating signal level at a1 and b1 is –5 dBm, and that the cou-

 

pling factor between AUT input and channel a1/ b1 input is ￿30 dB.

 

Thus, if measurements with an AUT input power of 1 watt (30 dBm) is

 

required, a 5 dB attenuator in each path is needed. In general,

 

attenuators are needed if Pin (max power at AUT input) is greater than

 

25 dBm and the value of attenuator is given by A (dB) = Pin (dBm) – 25.

 

Depending on the power output level of the preamplifier, two alternatives

 

exist for dealing withthe second issue.

Alternative 1

For moderate power levels (say up to 34 dBm at each preamplifier out-

 

put), the internal combiner can be used with a user-supplied circulator as

 

shown in the Figure 7-1. This will protect the combiner against a discon-

 

nected or mismatched AUT (e.g. power off) , but care must be exercised to

 

ensure that the source switch in the test set is correctly positioned before

 

power is applied to the preamplifier(s).

Alternative 2

For greater preamplifier power levels, an external combiner should be

 

used. Figure 7-2 is a suggested block diagram for this configuration.

 

PATS is designed to enable power calibrations in the presence of external

 

preamplifiers. For the flat power calibration, the user can specify his tar-

 

get power (at the AUT input which is the calibration reference plane) and

ME7840A OMM

7-1

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Anritsu ME7840A manual Chapter Preamplifier Operations, Use, External, Preamplifiers, Alternative
Page 106 Page 108

ME7840A specifications

The Anritsu ME7840A is an advanced test solution designed for characterizing and verifying the performance of wireless devices. With the rapid evolution of communication technologies, specifically in the realms of 5G and beyond, the ME7840A plays a crucial role in ensuring that devices meet the rigorous standards required for modern connectivity.

One of the primary features of the ME7840A is its high-performance vector signal analysis. It supports a broad spectrum of modulation formats, making it an ideal choice for testing a wide variety of wireless communication technologies. This includes LTE, NR (New Radio), Wi-Fi 6, and more. The system is capable of handling both uplink and downlink tests, providing a comprehensive solution for manufacturers looking to optimize their devices' performance.

Another key feature is its modular architecture, allowing for extensive customization based on specific testing needs. This flexibility means that users can mix and match different modules to create a tailored test setup that suits their particular requirements, whether they are focused on RF parameters, protocol conformance, or more specialized tests.

The ME7840A also integrates several advanced measurement technologies. For instance, its real-time signal analysis capability enables users to conduct in-depth examinations of complex signals, offering insights that can drive innovation and improve device reliability. Furthermore, this platform supports high-speed measurements with high accuracy, ensuring that manufacturers can achieve precise results in their testing processes.

Moreover, the ME7840A is equipped with automation features that streamline the testing process, significantly reducing the time and effort required to conduct tests. The system can be integrated into automated test environments, which is a key advantage for manufacturers seeking to enhance their production efficiency.

The Anritsu ME7840A's user-friendly interface also deserves mention. This accessibility ensures that engineers can quickly learn how to operate the system, allowing them to focus more on their testing objectives rather than on navigating complex software.

In summary, the Anritsu ME7840A is a versatile and powerful test solution that meets the diverse needs of the wireless industry. With its robust features, modular design, advanced measurement capabilities, and automation options, it is an essential tool for manufacturers aiming to stay competitive in today's fast-paced technology landscape.