5 Things You Need to Consider When Choosing a New RF Antenna

Can Anybody Hear Me? What Is RF Testing and Why It Matters
August 22, 2019

Silhouettes of satellite dishes or radio antennas against night sky. Space observatory.

The defense industry continues to drive innovation and growth of RF electronics. An RF antenna is a lot more complex and unique than what it appears on the outside. Knowing how to integrate an antenna in today’s electronics requires equal parts finesse and precise calculations.

Knowing which antenna performs best per application requires lots of testing and examining data sheets to account for all variables. With a rapidly-changing environment, you need a firm understanding of RF technologies and the differences in antenna types.

Here are five key points you should remember when choosing a new RF antenna.

1. RF Antenna Technologies

Antennas communicate with each other using radio waves created by an electric current. These radio waves are influenced by a number of factors in the environment. The board in which the RF antenna sits on must have the proper layout to achieve effective performance/communication.

Things start to get complicated when we’re talking about circuit boards the size of a child’s hand. Antennas also need to support various frequencies for wireless technologies, throwing another layer of complexity into the mix.

For example, you will need to consider how to optimize each of these different types of technologies:

GNSS (Global Navigation Satellite System)

These signals are among the hardest to pick up, known as L-Band signals from space. An antenna needs to have a grounding plane and amplifier to receive them, along with a radiating design for interference rejection.

Cellular Communication

These signals require multi-output antennas with the ability to confirm handshakes with the cellular networks. 5G networks require four antennas and four independent RF pathways.

WLAN (Wireless Local Area Network)

WLAN includes Wi-Fi and Bluetooth technologies. These have become standard among most electronic devices. RF antennas can be omnidirectional or focused in one direction for higher gains.

2. Gain and Losses

Gain is very important for determining the accuracy of the antenna’s reception. The higher the Decibels, the better the gain, and the clearer the signal becomes. Gain is not the same as power, also known as its wattage.

Gain is important for directivity but less important for electronics that use global positioning, WiFi, and etc. For two-way communications, the gain is often prioritized over transmission power.

3. Efficiency and Performance

Productivity is the most significant spec of RF antennas. It depicts the intensity which is provided to an antenna that is completely transmitted. In smaller, battery-controlled gadgets, accomplishing proficient execution is essential to the life span of the gadget.

Antennas are exceedingly sensitive to malfunctions, which can be brought about by impedance errors and detuning. This can come from conductive materials which might be put close to the antenna. Thus, the proficiency of an antenna environment will vary based on the simulated results in datasheets.

Ground plane length is another huge factor in deciding antenna productivity. Lessening the ground plane length by 20mm while working at sub-1GHz frequencies could make effectiveness fall by as much as 20%.

4. Voltage Standing Wave Ratio (VSWR)

The resistance measured against the alternating current via impedance is put into two categories: return loss or voltage standing wave ratio. VSWR can determine how much power is reflected back to the antenna. Lower VSWR means a stronger current going to the antenna.

Impedance matching involves matching the antenna module’s impedance with the RF. A high-quality RF antenna will contain low levels of resistance and gains above 50%. This is important when designing electronics that are energy efficient.

A lot of power is lost in RF circuitry if not correctly matched. A steady VSWR means less overall energy is wasted and the RF circuitry is supplied with consistent levels of power.

5. Testing for Sensitivity

How can you tell if the RF antenna you’ve selected is the right one for your needs? Lots of testing, even when the specifications far outweigh expectations. RF testing is needed for both design and technical purposes. 

No two devices operate with the same efficiency, so it is important to narrow down the variance and parameters for the end product. Engineers can only make an educated guess as to how sensitive an RF antenna is in a given environment. It is up to the manufacturer and client to produce results from extensive testing to hone the performance to specifications.

When designing the perfect device, the solution may not call for a custom antenna. Off-the-shelf retail products can save a lot of time and money, due to their known parameters. All of the extensive testing has been done and these antennas can easily be incorporated into devices.

When a custom antenna is ordered, the timeline of a project will vary. The engineering and testing process is not always straightforward. The known unknowns of getting the necessary performance from RF antennas are always a challenge, for successful enterprises and government contractors.

Find the Perfect Antenna

There is a lot of planning that goes into choosing an RF antenna for a specific need. On paper, it is deceptively simple as to what makes the perfect antenna. You want high performance, low sensitivity, and high efficiency. 

The catch here is that those numbers never reflect real-world performance. The PCB host itself can impact those numbers. You need to know how to cut through all the marketing noise and find the antenna that can enhance wireless capabilities.  

Rantec Antennas is where you will find the best selection of antenna technology. For both custom design and antenna prototypes, you’ll find exactly what you’re looking for with our experienced teams of engineers. Contact us today for a free consultation to learn what we can do for you.

We offer a unique guarantee in our manufacturing process. Rantec’s Quality Program is a documented, systematic plan created to support and meet the requirements for both military and commercial applications.

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