Tips to Improve Your SNR

July 29, 2019

Signal transmission from one point to another isn’t just about sending information between two channels.

The received signal should be an exact copy of the original waveform, without any changes in shape or waveform. However, this isn’t practically achievable. Signal transmission through a channel introduces several attenuation factors in the signal. These factors may alter the signal strength, frequency, or shape.

In order to determine the signal quality, engineers have developed a metric to separate the original signal from background noise. This metric is referred to as the SNR.

All about the SNR  

As the name suggests, a signal-to-noise ratio is an estimation of the original signal strength as compared to the noise element. The ratio is measured in terms of decibels and is mathematically represented as,

Tips to Improve Your Signal-to-Noise Ratio

Now that you know what an SNR is and its effect on your circuit, let’s talk about some of the methods that you can use to improve your signal-to-noise ratio.

š Using a Regenerative Circuit

Using a regenerative or a Q-multiplier circuit is an effective way to improve your SNR. This technique involves the use of an active filter with positive feedback. The input is amplified and then fed back to the circuit. This positive feedback has two effects; it attenuates any noise present in the circuit and strengthens the weak signal.

š Improving the Signal Strength

Improving the signal strength ultimately minimizes the noise effect on it. However, it’s important to remember that when we’re talking about improving signal strength, we’re referring to the original signal before transmission. Once the signal is introduced in the channel, it contains noise elements and amplifying this signal will amplify the noise components along with it.

Amplifying a signal before transmission will make it less susceptible to attenuation and distortion.

š Level Shifting

Although slightly complicated than the former two methods, level shifting is yet another effective method to improve your SNR. This method uses a local shifter and frequency mixer to sift the signal to another frequency band. This involves mixing your original signal frequency with the frequency of a local oscillator to create a signal that lies somewhere between this frequency range.

To better understand this method, consider an example where you’re mixing two frequencies of 89.8 MHz and 100.5 MHz. Your circuit will create a sum and a differential output by mixing these frequencies, giving you 190.3 MHz and 10.7 MHz output.

You can then choose your desired frequency range by passing your signal through a filter.

While we’re talking about improving your circuit’s SNR, let’s not forget the importance of using high-quality electronic components.

At ADSANTEC, we provide reliable electronic components with less susceptibility to noise. Our range of products includes 4-bit ADC, digital and FIR filters, signal splitters, phase detectors, delay lines, Logic gates, and several other electronic components.

Browse through our extensive selection of electrical components and to acquire the design solution you need.