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Ka-Band Spectrum Analyzer Functionalities

Key Takeaways

  • A device that measures and displays information about the signal amplitude with respect to variations in the frequency is called a spectrum analyzer. 

  • Real-time spectrum analyzers help discover invisible events in other spectrum analyzer architectures. 

  • The spectrum analyzer measures the amplitude response of the Ka-band signals received against frequency.

 Spectrum analyzer

Spectrum analyzers measure and display information about the signal amplitude with respect to variations in the frequency.

In engineering systems, spectrum analysis is a fundamental signal processing operation. The instrument used for spectrum analysis is called a spectrum analyzer. Depending on the frequency, different spectrum analyzers are employed for the measurement of signal distortion in audio systems, the monitoring of the licensed spectrum for allocation in various radio services, and electromagnetic emissions testing, among other things.

Ka-band frequency applications such as radars, military systems, space telescopes, microwave communication systems, and satellite communication use Ka-band spectrum analyzers. In this article, we will explore spectrum analyzers with a focus on their Ka-band applications.

The What, Why, and How of Spectrum Analyzers

The What 

A spectrum analyzer is a device that measures and displays information about the signal amplitude with respect to variations in the frequency. The signal amplitude data appears on the vertical axis or y-axis, whereas the frequency is plotted on the horizontal axis or x-axis. A spectrum analyzer is a wide-band receiver working on the principle of a superheterodyne receiver. 

The Why 

Signal processing is an unavoidable part of any system dealing with signals. Analyzing the signals aids in determining whether the signals are within prescribed limits. The spurious signals present in the original signal can be identified through spectrum analysis. Similarly, the presence of transients, glitches, burst transmissions, noise, complex waveforms, etc. can be checked through the process of spectrum analysis. The masking of weaker signals by shorter signals can be recognized through analysis of the spectrum received. For analyzing spectrums, spectrum analyzers can be utilized.

The How 

The spectrum analyzer converts the frequencies, typically ranging up to hundreds of GHz, to measurable values. The frequency spectrum received is swept through a range of preselected frequencies. The selected frequencies are converted to measurable DC levels. The selected signal strength is displayed against the frequency. 

Differentiating Spectrum Analyzers From Oscilloscopes

SI. No

Spectrum Analyzer



Displays signal amplitude against frequency (frequency domain analysis)

Displays signal amplitude against time (time domain analysis)


Amplitude response of the signal is measured in a dBm in spectrum analysis

Measurements are in volts in oscilloscopes


Suitable for measuring low amplitudes and high frequencies

Preferred measurements are for low-frequency, high amplitude signals


Complex circuitry is involved, cost of the analyzer is high

Cost of the oscilloscope is lower than spectrum analyzers

Types of Spectrum Analyzers

In the radio-frequency ranges, evaluating the circuit and system characteristics can be carried out using a spectrum analyzer – also known as a frequency analyzer. Generally, spectrum analyzers are classified into the following.

  1. Swept Spectrum Analyzers or Super Heterodyne Spectrum Analyzers

This is the traditional type of spectrum analyzer used for measuring controlled static signals. In a swept spectrum analyzer, the signal received is converted into power vs. frequency measurements and swept through a passband resolution bandwidth filter. The detector that follows the resolution bandwidth filter calculates the signal amplitude corresponding to the selected frequencies.

  1. Vector Signal Analyzers

For analyzing digitally modulated signals, vector measurements are required. The vector measurements give information about both the magnitude and phase of the signal. The RF power received within the passband of the spectrum analyzer is digitized and stored in the memory. The data can be utilized for display processing, measurements, or demodulation.

  1. Real-Time Spectrum Analyzers

Real-time signal processing is employed in real-time spectrum analyzers. Real-time spectrum analyzers help to discover invisible events in other spectrum analyzer architectures. 

Applications of Spectrum Analyzers

Spectrum analyzers are used in wifi testing, electromagnetic interference hunting, radar testing, voice and data communication, spectrum allocation, and digital video. Let’s look at a specific application of spectrum analyzers using the Ka-band frequency spectrum.

Ka-Band Spectrum Analyzers

The Ka-band frequency spectrum (ranging from 27GHz to 40GHz) is widely used in satellite communications, radar applications, military systems, radio astronomy, etc. In Ka-band applications, spectrum analyzers are typically used for three functions.

  1. Frequency response measurements - The spectrum analyzer measures the amplitude response of the Ka-band signals received against frequency

  2. Monitoring power - The transmitted and received power in Ka-band systems can be measured using a spectrum analyzer. The spectrum analyzer helps in verifying whether the Ka-band signals are within the specified values.

  3. Signal interference measurements - The Ka-band installations require a site survey. The spectrum analyzer can be used to identify and verify the interferences affecting the Ka-band systems.

Other Applications of Ka-Band Spectrum Analyzers

Ka-band spectrum analyzer applications are not limited to:

  1. Spurious signal measurements
  2. Inter-modulation measurements
  3. Return-loss measurements
  4. Satellite antenna alignment
  5. Harmonic measurements 

Cadence’s suite of PCB design and analysis tools can help you develop Ka-band applications, including radar systems, military systems, and satellite communication systems. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.