What are the Most Common Types of Communication Antennae?

Quick Definition:  The most common communication antennas include dipole antennas, monopole antennas, Yagi antennas, patch antennas, and parabolic antennas. Each antenna type has unique purposes and varying pros and cons.

Nothing speaks to the advancement of our civilization like the antennas that dot our countryside and inhabit our smartphones. These communication devices profoundly affect how we transmit data, communicate, and broadcast. While they all play the role of transmitting data, antennas are not built the same and are vast and varied. Let’s go over the myriad antenna types and their relevance to the Network+ Exam and our everyday lives. 

What are the Most Common Types of Communication Antennas?

The number of communication antenna types is vast, so we’ll walk through several of the most common types and their purposes and specialties. Generally, people interact most often with dipole, monopole, Yagi, patch, and parabolic antennas. Let’s go over what each of those do, along with their pros and cons, starting with dipoles.  

The following chart provides quick access to facts about each antenna discussed.

What are Dipole Antennas?

Dipole antennas are basic antennas used to broadcast radio frequencies. Dipole antennas get their name from two conductors of equal length that extend from each side of the antenna. Dipoles are omnidirectional antennas, meaning they broadcast frequencies in all directions simultaneously.

Dipole antennas have a plethora of uses, ranging from television broadcasting, aircraft communication, AM/FM radio, and military applications. The biggest advantage of dipole antennas is their wide range of use and simplicity.

The benefits of a dipole antenna include: 

• Wider Bandwidth: Compared to monopole antennas, a dipole antenna has a wider operation bandwidth. This works great when you need to broadcast at a higher range of frequencies.

• Directionality: Bidirectional antennas provide more focused broadcasts on the axis where the directional poles extend. This provides the ability to extend the frequency range farther than, say, a monopole antenna.

• Balance Configuration: Dipole antennas have a balanced configuration with two equal-length elements. This often results in a more balanced radiation pattern and better performance in certain situations.

Despite their benefits — and how commonly they are used — there are some disadvantages of dipole antenna, including: 

• Limited Bandwidth: Dipoles typically have a narrow bandwidth compared to some other antenna types. This means they may not perform optimally over a broad range of frequencies without adjustments. They are more suited for narrow frequencies.

• Large Size: As with most antennas, the size of the antennas is proportional to the frequencies it captures. The lower the frequency, the bigger the antennas. That is why dipole antennas are often unsuitable when size is a concern; it may be better to use a patch antenna instead.

What are Monopole Antennas?

A monopole antenna is a type of antenna that consists of a single, conducive element. Like dipole, it is omnidirectional and used for a range of purposes. If you have ever seen a large plastic “stick” protruding from a car, old cell phone, or router, then you’ve seen a monopole antenna. Most often, monopole antennas are used to broadcast mobile communication, AM/FM radio, navigation systems such as GPS, and television broadcasting.

Monopole antennas have several benefits, including: 

• Compact Size: Monopole antennas are often smaller than their dipole counterparts. Their compact size makes them a more practical choice when the real estate is limited. However, monopole antennas can also be towers stretching into the sky to catch and broadcast radio signals.

• Simplicity: The simplicity of monopole antennas makes them a low-cost and effective solution for data transmission. That’s why they are often used to broadcast radio, television, and even WiFi. In fact, whenever you see an old car with a radio antenna or a wife router with a large plastic stick protruding out of it, these are monopole antennas. 

Monopole antennas are not suitable for all situations. What are the drawbacks of monopole antennas? 

• Ground-Dependent: The biggest drawback to monopole antennas is that they are ground-dependent. Monopole antennas rely on a conducting ground plane for them to function properly. When a proper ground plane is not available or is altered, the antenna's performance can be affected.

• Efficiency Concerns: Monopole antennas can be affected by buildings or other nearby obstructions. The presence of obstacles can seriously degrade its performance. 

What is a Yagi Antenna?

The Yagi antenna’s hallmark feature is its multiple parallel elements. Often, you will see Yagi antennas on top of apartment buildings, retrieving TV broadcast signals. Unlike the previous two antennas discussed, Yagi antennas are not omnidirectional, but directional antennas. 

Think about the following scenario. You’re watching a baseball game at your friend's apartment. Suddenly, the TV gets fuzzy and choppy. To correct this, your friend heads to the apartment's roof, adjusts an antenna, and corrects the issue. It is a typical-looking antenna with multiple prongs sticking out of it. This would be an example of a Yagi Antenna. 

What are the benefits of a Yagi antenna?

• High Gain: The best aspect of Yagi antennas is their high gain. “Gain,” in the context of antennas, is its ability to focus energy in a particular direction. It is a measure of the intensity it can direct energy toward the intended target or the sensitivity with which it can receive intended transmissions. Yagi antennas are excellent at point-to-point communication in a specific direction. That’s why they are often used to receive TV broadcasts. 

• Excellent for Outdoor Usage: Due to its robust design, the Yagi antenna is excellent for outdoor usage. Yagi Antennas are made with anti-corrosive material, wind loading, and waterproofing to ensure excellent signal coverage. 

• Cost-Effective: Yagi antennas are often cost-effective, especially for the level of gain they provide. This makes them a practical choice in scenarios where a balance between performance and cost is essential.

Drawbacks of Yagi antenna include: 

• Fixed Directionality: Yagi antenna’s fixed direction characteristic may be one of its biggest setbacks. This means they have to be pointed in a specific direction to work properly, and when knocked out of place, service disruption can occur. 

• Yagi Antennas are Big: Yagi antennas are fairly large, especially ones broadcasting lower frequencies. This makes them difficult to maintain and complex to mount. Additionally, they quickly become unsuitable for applications that require a more compact solution. 

What is a Patch Antenna?

Patch antennas are compact, conventional antennas, also known as microstrip antennas. Their namesake comes from the fact it looks like a small metal patch. It was created for situations where considerations such as size, weight, and aerodynamics are paramount. These directional antennas can be found in iPhones, jets, satellites, and other places where size and quality are paramount.

In smartphones and other IoT devices, patch panels are perfect for transmitting WiFi signals. If patch panels did not exist, your Android or iPhone would likely have a monopole antenna sticking out of it, like in the days of old.

What are the benefits of patch antennas?

• Light Weight: Patch panels are lightweight, which contributes to their suitability for applications where weight is of the utmost importance. Namely, smartphones and aerospace technologies.

• Convenient RFID Application: Patch antennas are commonly used in Radio-Frequency Identification (RFID) systems for tracking and identification purposes. Their compact size and performance characteristics make them well-suited for this application.

• Low Cost: Patch panels are cost-effective to manufacture due to their compact nature. This makes them an economical option when budget constraints are a factor.

What are the drawbacks of a Patch Antenna?

• Narrow Bandwidth: Patch antennas have a narrow bandwidth, so they are less effective in situations where a broad range of frequencies is required. 

• Sensitivity to Cross-Polarization: Patch antennas can be sensitive to cross-polarization, meaning they may pick up signals that have a polarization orthogonal to their intended polarization. This sensitivity can be a limitation in certain environments. 

• Temperature Sensitive: Patch antennas can be temperature-sensitive due to their small size. They have a liability to malfunction or melt altogether. That’s why you should never leave your iPhone or Android in a hot car in the summertime!

What is a Parabolic Antenna?

The last item on our whirlwind antenna tour is the parabolic antenna. This is the most high-tech-looking antenna and what most people probably think of when they hear the word 'antenna.' It is your standard bowl-shaped antenna that you might see on radar systems, satellite communications, or even installed by DirectTV.

The most apparent piece of a parabolic antenna is the large, bowl-shaped structure. This is called a reflector and is used to direct radio frequencies in a specific direction, increasing the antenna’s sensitivity when receiving data.

At the center of the paraboloid is the feed antenna, often called a feed horn. Located at the focal point of the reflector, it is responsible for generating or receiving electromagnetic waves. The feed antenna is usually a small dipole, horn, or other antenna type designed to emit or capture the signals.

What are the benefits of parabolic antennas?

• High Gain: Parabolic antennas have the highest gain values. That is why they are regularly used to communicate with satellites in outer space. 

• Highly Focused: Thanks to their parabolic reflectors, these antennas are effective in capturing weak signals from distant sources. That’s what makes them so useful in radio astronomy, where faint signals from celestial bodies need to be detected.  The ability to focus on a specific region of the sky is crucial.

• Highly Directional: Parabolic antennas are highly directional, meaning they can concentrate their radiated or received energy in a specific direction. This property is beneficial for point-to-point communication, such as a telephone call or satellite communication, where the ability to focus on a particular target is essential.  

What are the drawbacks of parabolic antennas?

• Bulky Size: Parabolic antennas can be large and bulky, especially at higher frequencies. The size of the dish is directly related to the wavelength of the signals it is designed to handle. This can be a limiting factor in applications where space is constrained.

• Require Precise Alignment: Due to their ability to project to outer space, parabolic antennas are very expensive to align and maintain. This limits their usage to only the most important job that only a parabolic antenna can handle.

Conclusion

As you may have noticed, there are several different antenna types, and each is suited for a specific purpose. For compact solutions, choose the patch antenna. For point-to-point communication, a Yagi or parabolic antenna is perfect. If you simply need an affordable solution to broadcast radio, TV, or Wifi, a dipole or monopole antenna will serve as an adequate solution.

Also, remember that gain determines how far an antenna can transmit and also how sensitive it is to picking up signals. Lastly, omnidirectional antennas broadcast in all directions, while antennas need to be pointed in a specific direction to guarantee optimized efficiency. All of this and more can and will be covered on the Network+ Exam. So make sure you have a decent understanding of these concepts before taking the exam. Good luck!

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