Last updated on October 21st, 2020 at 04:28 am
A spectrum analyzer is a type of equipment that can show signal strength as amplitude against a signal frequency. The signal amplitude is shown on the vertical y-axis whereas the frequency is shown on the horizontal x-axis.
Spectrum analyzers often resemble an oscilloscope and, as a matter of fact, many of these devices can work interchangeably. Spectrum analyzers are used for examining audio signals as well as the frequency spectrum of radio frequencies (RF).
The performance of a circuit, as well as the individual elements of a signal, can be monitored by using a good spectrum analyzer. The device is used by individuals as well as businesses to study many types of circuits and waveforms.
An organization can use this instrument to find out the needed changes that may have to be made to eliminate interference or to improve the performance of a particular network like a wireless router or a Wi-Fi system.
A spectrum analyzer can also be used to find out the bandwidth of an analog or digital signal.
So, whether a person wants to find out a home’s wireless internet signal or an organization or company wants to determine the site of its next cell tower, a spectrum analyzer will be needed for all these varied tasks.
Signal analysis has been at the forefront of innovation and research in the last few decades.
Even simple jobs nowadays need adept analysis of signals and waveforms. These sophisticated devices can be very helpful in observing all types of signals.
While the former two types are examples of the digital spectrum analyzer, a real-time analyzer is more of a hybrid nature.
These can be used as per their suitability for a job. It also must be mentioned here that handheld analyzers are very much used nowadays as they lend considerable ease-of-operation and can be sufficiently portable for many types of work.
In the following sections, we will take a look at some of the good spectrum analyzers that are easily available in the market for any of the mentioned uses.
Best spectrum analyzers comparison
The five top spectrum analyzers
It is a light and compact spectrum analyzer that can assure superb result for all types of applications.
It has a large display with a fine resolution that can help in determining all types of signals with useful functions like Auto Range, Auto Couple, Auto-Tune and Auto Scale.
All these functions can be helpful to select parameters automatically so that people can save time instead of manually operating an analyzer.
- Wide frequency range: The spectrum analyzer has a wide frequency detection range from 9kHz to 1.5 GHz and can, therefore, be helpful for many purposes like education, manufacturing as well as company research.
- Easy tracking can be done: With this device, easy tracking can be done as it comes with a 1.5 GHz tracking generator.
- Lots of added functionality: The equipment offers automatic signal acquisition and also has marker table functionality that can be helpful for many types of jobs.
- Compact and lightweight: The equipment only weighs 11.9 pounds and that can be a very lightweight and compact option for many customers who may need it at various places.
- A large and clear display: The device has a very large display of 20.3 cm that provides a resolution of 800X480 pixels that can make viewing quite comfortable.
- Many additional features: The unit comes with many remote communication interfaces and an easy-to-use numeric keypad that makes it very easy to operate for users. It also offers AM/FM demodulation plus a preamplifier to amplify smaller signals.
It can easily be connected to a computer or laptop through its standard mini-USB 2.0 connector to access all the extra functionalities.
The tuning of the device is quite accurate and for any small job, it can be the best fit. You can also download its software and see all the data on a larger screen using it so that there is a better understanding.
- Wide frequency range: This spectrum analyzer predominantly covers frequencies within the range of 240 to 960MHz. All major sub 1GHz ISM bands including the popular ones like 315 MHz, 433 MHz, 868 MHz, and 915 MHz and inclusive of the UHF TV, GSM, and 33 cm and 70 cm HAM radio are covered by it.
- There are a lot of modes: This best budget spectrum analyzer comes with a lot of modes like Averaging and Overwrite modes, Hold and Peak Max, Normal, etc.
- Highly extendable: For better functionality and additional bands, the device can easily be extended with internal expansion modules.
- Scalable software: Its software can easily be used on any system as it is supported by Windows PC client Open Source.
- Extended back-up and rechargeable: The device has a high capacity Li-ion battery that can provide a continuous run for more than 16 hours so that there is non-stop support at all times. Moreover, it can be charged through its USB port.
- Lightweight and portable: At 9.8 ounces, it is a pocket size device and is quite lightweight so that it can be carried anywhere.
- Upgrades available: The equipment features a free lifetime firmware upgrade that can be accessed by the community.
It is a digital handheld spectrum analyzer that works for all types of major frequency bands. The equipment has been designed on the model of a double balanced mixer and a sophisticated frequency synthesizer so that it offers optimum performance, low power consumption, and economic cost.
It features a state-of-the-art expansion module and has a 6G baseline unit. There are two SMA connectors along with three antennas – a Nagoya NA773 wideband antenna for all types of Sub-GHz frequencies, a whip helical for the 2.4GHz band, and a rubber duck of 5.8 GHz.
In addition to these, there is provision for connecting band antennas to cover some other supported frequencies. The instrument is capable of covering most communication frequency ranges that are used in modern communication like Wi-Fi, wireless audio and video, satellite, DTV, CATV, Bluetooth, LTE, GPRS, and GSM.
- Large frequency bands: It offers two types of frequency bands from 15MHz to 2.7GHz and 4.85GHz to 6.1GHz with an amplitude resolution of 0.5dBm
- Portability: This best buy spectrum analyzer is lightweight and portable with a product weight of only 6.6 ounces.
- All latest upgrades: The latest firmware upgrades are available with it including the Wi-Fi Analyzer.
- Easy analysis: Free Windows and Mac software is available for analyzing Wi-Fi and RF networks by using the Waterfall 2D and 3D.
- Extra safety: The equipment can stay protected amply in the aluminum case so that all the parts and components can stay organized.
- Sufficient support and warranty: The instrument comes with full support from RF Explorer and the company has also extended a 2-years warranty on the product.
The unit also offers a better dynamic range feature for less spurious signals and can be customized for interference hunting, education or IOT (Internet of Things).
- Portability and ease of use: This best budget spectrum analyzer comes with SignalVu-PC vector analysis software for ample portability so that it can be used with a laptop or tablet. Real-time signal analysis can be done using it both in the lab as well as for field applications.
- On-the-spot analysis: Features like the portable form factor, radio signal recording, and scanning facilities can help with on-the-spot spectrum analysis.
- Determine interference sources: With increased mobile tower penetration in each area, interference may have to be determined at many places for other electronic equipment. It is easy to identify interference using the RSA600.
- Improved Dynamic range: There is optimum analysis capability along with advanced measurement options with its 15 packages that cover spectrum management, major wireless standards, pulse management, etc. so that an improved dynamic range can be enjoyed.
- Easily customizable: The unit can be configured using the RSA306B and the signal Vu-PC so that many types of applications like interference hunting, IOT or education can be facilitated.
- Highly affordable: It offers a free signal Vu-PC signal and moreover, it is priced at half the cost of a conventional spectrum analyzing equipment.
It can be used for many types of applications that include education, maintenance, research and development, production along with a large number of other areas.
The device also comes with a standard preamplifier so that all types of signals can be properly amplified.
- Wide frequency range: This completely digital, IF technology analyzer offers a wide frequency range of 9kHz till 2.1 GHz, and that can be a really wide band for any type of analysis.
- Decreased noise level: The displayed average noise level of the device is 161 dBm/Hz, whereas the offset phase noise of the unit is pegged at 98 dBc/Hz at 10 kHz.
- Superb accuracy: It offers an overall amplitude accuracy of less than 0.7 dB that can be very much favorable for most applications.
- Attractive resolution bandwidth: The equipment has a 10 Hz minimum resolution bandwidth and that can be very helpful.
- Signal amplification: Adequate signal amplification can be achieved by its standard preamplifier.
- Large display: The analyzer has a 10.1-inch WVGA display with a resolution of 1024 X 600 pixels for a clear viewing experience.
How to choose the spectrum analyzer?
Selecting the high-quality spectrum analyzer may not be easy at all times. It needs a careful understanding of one’s requirement as well as a deft knowledge of the various analyzers that are available in the market.
Today, there are a lot of options that can be easily available. However, understanding the major parameters of this device is important so that efficient equipment can be selected. In the following sections, we take a look at nine important parameters that can help in deciding a spectrum analyzer.
Frequency range: Depending on the limits and frequency range, the best budget spectrum analyzer price can be determined.
However, for higher frequencies, a range can depend on an analyzer’s mixing system and any added filtering needs. In the higher spectrum bracket, there can be three types of choices.
- An up/down converter having many IF stages : This type of low-frequency system can work from a few kHz to 3 or 4 GHz.
- A harmonic mixer: These are mainly used for microwave spectrum analyzers. Preselected and non-preselected analyzers work for frequencies that are in excess of 100GHz. The higher frequency mixers make use of waveguide technology.
- A digital sampling spectrum analyzer: This type of analyzer makes use of a digital IF system in association with either of the above types. Single conversion mixing of up to 3 or 4 GHz may also be used by them.
Level range: The needed level range for an analyzer can be one of its most important considerations. It is defined as the maximum input power handling capacity of its input attenuator. Generally, it is between 100 mW and 1 Watt. At times, the reference set can also be seen. A detailed evaluation is needed to find out the best buy spectrum analyzer for all the performance, price and various other options.
An equipment’s noise floor is the displayed average noise level (DANL) that is highlighted in data sheets for a given set of condition. Some manufacturer may mention DANL at 10 Hz whereas others may quote the figure at 1 kHz. DANL depends to a large extent on the resolution bandwidth (RBW) and hence RBW must be normalized for different analyzers so that they can be compared in the best possible way.
Display range: It is yet another specification that can help in determining the top rated spectrum analyzer. The display range is the product of a unit’s vertical scale range and its graticule size. Usually, a display has a display range of 80 or 100 dB with 8 or 10 graticule steps with 10dB/div.
If an analyzer has 8 graticule steps with 20 dB/div, then the display range will be 160 dB. It may seem to be quite attractive at first but then, the dynamic range of the unit must also be taken into account.
Dynamic range: The concept of dynamic range in an analyzer must be understood correctly so that a piece of desirable equipment can be purchased. A dynamic range is defined as the ratio of the largest signal that can be handled by the equipment satisfactorily without any distortion and noise floor. It is important here to remember that the largest signal and the noise floor should happen at the same instant of time so that a plausible dynamic range is achieved.
Resolution bandwidth: The resolution bandwidth is typically the bandwidth of an equipment’s IF filter. It helps in finding out the selectivity of the device.
For achieving wide sweeps, a wide resolution bandwidth is needed and vice versa. However, for higher resolution, there can be a slower sweep speed whereas, for narrower bandwidths, the sidebands can be exposed. Hence, a careful trade-off is needed while selecting.
Frequency accuracy: Frequency accuracy can be a generic term for a spectrum analyzer as there are three types of frequency specifications within the device. For the best buy spectrum analyzer, it’s reference-frequency accuracy is highly valued. Apart from it, there is also the span accuracy and center-frequency accuracy.
It has a swept local oscillator and there are three operational modes in it that have different frequency accuracy details. These three modes are known as the Free Run mode, Lock and Roll mode, and the stepped-sweep mode.
Level accuracy: A constant level accuracy is highly needed for the best spectrum analyzer. To meet this end, an internal calibration signal is used so that changes in the IF amplifier gain can be modified accordingly and a constant level accuracy can be obtained.
Initially, when an analyzer is produced, a power meter system and a signal source are used to determine the instrument’s frequency response characteristic and the input level. The level accuracy can be changed later as per a need by using the same technique.
Distortion and spurious signals: No one will enjoy distortion or spurious signal while taking a measurement on an analyzer. Sometimes, there can be a signal displayed on the screen without any signal being there at the input! This phenomenon is known as residual response and it can be inherent in all types of devices to some extent.
It is recommendable to get an analyzer that offers minimum residual response and that should not be more than -110 dBm. However, the preferred range should always be less than -115 dBm that can ensure accurate analysis of an input signal.
Sweep speeds: Sweep speed can be an important criterion while selecting the best buy spectrum analyzer and it can depend heavily on the frequency resolution of the device. The sweep speed of an instrument must be low enough so that a signal settles comfortably within its narrow resolution filter.
Latest analyzers use microprocessors for the purpose so that the best speed can be achieved. When high resolution is needed, the sweep speed may have to be as low as 100 seconds and in such an instance, digital storage will be highly needed. Also, to keep a check on automatic selection, users can also go for a manual sweep speed controller so that the desired level can be achieved.
Frequently Asked Questions (FAQ’s)
Are there many different types of spectrum analyzers?
Answer: Yes. There can be basically two types of spectrum analyzers – Swept-tuned Spectrum Analyzer and Fast Fourier Transform (FFT) Analyzer. The use of each of these types is governed by the way in which a signal spectrum has to be realized. A swept-tuned spectrum analyzer employs a superheterodyne receiver so that an input signal can be converted to the mid-frequency of a band-pass filter. It makes use of a mixer and a voltage-controlled oscillator.
By using superheterodyne set-up, a voltage-controlled oscillator can cover wide frequency ranges so that the complete frequency range of a device can be covered. In a Fast Fourier Transform (FFT) analyzer, the input signal is analyzed using a Discrete Fourier Transform (DFT) method. A DFT is a type of mathematical process that converts a waveform into its individual components that are there in its frequency spectrum.
How is each type of spectrum analyzer differentiated?
Answer: Apart from the type of signal that it measures, a spectrum analyzer can also be classified into an analog, digital or hybrid variant. While analog analyzers are not used much these days, digital analyzers are more in vogue due to their relative ease of use and a large number of features. Hybrid spectrum analyzers are also preferred for certain applications.
Digital spectrum analyzers are sophisticated devices and can handle complex tasks using the Fast Fourier Transform (FFT) technique. They can also help in analyzing optical or electrical signal components that can be much smaller. With a digital analyzer, the task of analyzing a signal can be very simple. Each analyzer can be distinguished based on its bandwidth rate, frequency, sweep rates and resolution.
How to determine whether to use a benchtop device or a handheld spectrum analyzer?
Answer: There is no set rule to select a benchtop or a handheld device for a particular purpose. While a benchtop device can offer advanced specifications and a lot of features and applications, they can tend to be bulky for many operations. On the other hand, a handheld spectrum analyzer can be portable and will be well-suited to field-related activities.
Users of the device who spend more time in the field can be benefited by its use. However, for advanced analysis of waveforms and signals in a lab, a benchtop can be highly desired.
What type of frequency range is usually covered by a spectrum analyzer?
Answer: An extensive spectrum range is covered by spectrum analyzers so that users can analyze signals from a few kHz to 50 GHz and even more. There are some manufacturers which offer signal analyzing capabilities for frequencies up to 325 GHz by making use of external mixers in the device. Hence, a large frequency range can be easily targeted with it for efficient analysis.
Can a spectrum analyzer demodulate signals?
Answer: Yes. It is perhaps one of the most important benefits of using a spectrum analyzer. When demodulated signals need to be transmitted, a modulated signal can be demodulated using a modulation analysis software. This type of software is provided by many spectrum analyzer manufacturers. A large number of general usage and standard signals and formats can be demodulated in this way.
How can we get a higher sensitivity from a spectrum analyzer?
Answer: Getting a high sensitivity is always desired from any spectrum analyzer and to realize it from the measured signal, the center frequency, reference level, and span has to be set at the beginning. After setting these parameters, if there is no overload condition then the attenuation value should be reduced slowly. Now, if the measured signal has a Signal-to-Noise Ratio (SNR) lower than 15 dB it is advisable to slowly decrease the RBW value. When RBW is low, the noise floor will also be minimum and there will be a high sensitivity.
We have seen here the basics of a spectrum analyzer and how it can be helpful for observing many types of signals. The spectrum analyzers that are available in the market have also been discussed in detail so that a customer can make an informed choice. The selection criteria for the device has also been delved in detail to help users understand the different features and how they can be helpful for an application. Additionally, some of the FAQs regarding the equipment has also been covered here that can provide a detailed understanding of many aspects of the device.
However, after going through all of them, we can surely say that the Rigol DSA815-TG spectrum analyzer can be the chosen choice for a lot of applications. However, depending upon preference and particular nature of work, other ones can also be selected as per requirement. Irrespective of which brand is selected for a particular application, a spectrum analyzer can help a wide variety of users and their utility just cannot be neglected. Moreover, with a lot of features that the digital and hybrid variants of the device offer, it can surely help in aiding a lot of processes.