How to choose a signal generator and adjust the sensitivity of the signal generator?

Cecelia Qiu Cecelia Qiu 11 February 2022 Follow
How to choose a signal generator and adjust the sensitivity of the signal generator?

1. Application of signal generator in sensitivity

The sensitivity of the radio and the walkie-talkie can be adjusted by the signal generator. The basic principle of adjustment is to minimize the attenuation of the useful signal transmission by the filter slot in the transceiver's receiving channel so that the walkie-talkie has higher sensitivity. Under normal circumstances, this method is more used in the frequency conversion of amateur radio stations and self-made radio stations. In this process, the role of the signal generator is to simulate the air signal. Consider a situation where the walkie-talkie itself has a received signal strength S meter or test point, you can use the signal generator to input a signal to make the machine signal meter indicate about 30% strength (it's easy to see the effect of the adjustment ), and then make appropriate adjustments according to the instructions in the radio's maintenance manual. If the signal meter is full during adjustment, the signal amplitude of the signal generator can be reduced. Usually, in order to ensure the sensitivity of the whole frequency band, it is necessary to use multiple frequency points at the high end, the end and the center of the target frequency band as the reference point of "uniform tuning" in order to obtain the average value. If the walkie-talkie does not have the function of signal strength indication feedback, then we can only make step-by-step adjustments to the receiver by monitoring the improvement and degradation of the signal-to-noise ratio under the condition of a low signal-to-noise ratio. Whether it's a walkie-talkie, a radio, or a TV, the sensitivity of signal generators can be adjusted by producing the same type of signal.

How to choose a signal generator and adjust the sensitivity of the signal generator?

2. Four elements of signal generator selection

a. Meet the signal types and functions required by the application


According to practical experience, it can be known that vector signal sources are more suitable for testing digital signals; while ordinary function generators are often used in two aspects, one is in basic circuit experiments, and the other is for repairing ordinary electrical appliances; and high-frequency Signal generators are often used in applications that require high sensitivity.

b. Meet the frequency range and output amplitude range required by the application

In order to meet the needs of actual use, when selecting a signal generator, it is mainly necessary to consider three aspects of the signal generator: one is its frequency coverage, the other is its modulation mode, and the third is its signal output amplitude.

c. The price is within the budget

When choosing a signal generator, price is a factor that must be taken into consideration. Usually, the performance of a high-end signal generator is greatly improved from that of a low-end signal generator. However, high-end signal generators also mean higher prices on the other hand. If your application scenario does not have particularly high-performance requirements, choosing a low-end signal generator may be a good choice. If your application scenario has high-performance requirements, but your funds are insufficient, you can consider leasing.

d. Reliable after-sales guarantee

The signal generator is already one of the high-priced electronic equipment, so when we purchase, we must consider the problem of fault maintenance of the signal generator, that is, we must consider the after-sales guarantee. If there is no reliable after-sales guarantee, then when the signal generator fails, we may need to spend more money.

3. Pulse signal generator

A generator that produces rectangular pulses of adjustable width, amplitude, and repetition rate that can be used to test the transient response of linear systems or use analog signals to test the performance of radar, multiplex communications, and other pulsed digital systems. The pulse generator is mainly composed of a master oscillator, a delay stage, a pulse forming stage, an output stage, and an attenuator. The main control oscillator is usually a circuit such as a multivibrator. Except for self-excited oscillation, it mainly works in a trigger mode. Usually, a pre-trigger pulse is an output first after the external trigger signal is applied to trigger the oscilloscope and other observation instruments in advance, and then the main signal pulse is output after an adjustable delay time, the width of which can be adjusted. Some can output a pair of main pulses, and some can output two main pulses with different delays respectively.

Follow the link to learn more about the signal generator.

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