Types of WiFi Antennas: A Complete Guide

In this modern and fast-paced world, everything is advancing, and communication systems has evolved. In the early stages, we relied on wired communication schemes, but due to the advancement in technology we have transitioned into wireless communication. Today, WiFi is everywhere, and WiFi antennas are one of the essential parts of our daily lives. They are almost like a silent companion for us, ensuring we stay connected wherever we go.

Wireless communications depend on radio frequency energy, which is transmitted and received through WiFi antennas. So, the quality of the WiFi antennas directly affects the coverage and performance of your networks. So, understanding the basics will help you to choose the correct antenna next time you need one.

Now, let’s take a closer look at what exactly Wifi antennas actually are. An antenna is a device that radiates radio waves when it receives electrical power and can also convert the radio waves back into electric power. In the context of WiFi, antennas are crucial components and they help to transmit and receive radio frequency signals, allowing devices to connect to the internet. They can also act as both transmitters and receivers, enabling a smooth connection between devices.

WiFi antennas are essential in our wireless world. Our day-to-day devices like smartphones, computers and laptops rely on antennas to send and receive data. In homes and offices, WiFi antennas ensure smooth internet connections for daily activities like video streaming, browsing and gaming. They also enable public WiFi hotspots in places like cafes, restaurants and airports. WiFi antennas also play a crucial role in the world of IoT (Internet of Things). Additionally, these WiFi antennas are key in long-range wireless internet services. WiFi antennas power the growing trend of wireless audio systems, allowing devices to communicate without the need of any physical connections.

After understanding what WiFi antennas are and the importance of them, let’s dive into the key factors that make these antennas work effectively in different situations.

Understanding WiFi Antenna Parameters

WiFi antennas are defined by several important parameters, that determine their performance and the suitability for different tasks. Let’s break them down to make it easier to understand.

Gain

The gain of an antenna is a measure of its ability to focus energy in a specific direction, compared to a theoretical reference antenna called an isotropic radiator. An isotropic antenna is a device which radiates energy equally in all directions, has a gain of 0 dBi (decibels over isotropic).

Antenna gain is measured in dBi, and it represents the antenna’s efficiency in directing electromagnetic waves. Higher gain means the antenna can reach further distances and provide stronger signals. However, higher dBi doesn’t always mean better. As the antenna’s dBi increases, it can send signals farther, but it will cover a smaller area. Imagine it like a flashlight beam, a higher gain means a more focused signal, which could result in less coverage in other directions.

Radiation Pattern

Radiation is a term used to represent the emission of wavefront at the antenna, specifying its strength. An antenna’s radiation pattern shows how the antenna transmits radio frequency energy in different directions. This pattern is important for both communication and designing effective systems. It is usually shown in polar or cartesian coordinate systems. These patterns help us see if the antenna can focus energy in a specific direction or spread it out evenly. For example, the radiation pattern of an omnidirectional WiFi router resembles a doughnut shape, as it radiates radio waves with equal strength in all horizontal directions.  An omnidirectional antenna is designed to spread signals evenly in all directions around it.

Frequency Range

We know that WiFi devices communicate with each other through radio waves. Radio waves are characterized by their frequency—the number of cycles per second, measured in Hertz (Hz). According to the technology used, WiFi antennas utilize several frequencies to transmit information: 900 MHz, 2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz and 60 GHz. The most typical frequencies are 2.4 and 5 GHz band which corresponds to wavelengths 12.5 cm and 6 cm {wavelength(m) = 3x 10⁸ms^-1/frequency (Hz)}.

Lower frequency waves have longer wavelengths, which make it easier to pass through obstacles like walls and metals, allowing signals to travel farther. Each WiFi antenna is built to match the exact frequency and wavelength of the signal is being transmitted. In simple terms a 2.4 GHz antenna cannot replace a 5 GHz antenna and vice versa. But some antennas like dual-band antennas have the ability to utilize both frequencies.

Connector

When we talk about WiFi antenna connectors, there are several styles commonly used. Connectors are important for attaching external antennas to WiFi devices such as access points and routers. Common types include,

• RP-SMA (Reverse Polarity SMA): It is a widely used connector in consumer devices, with reversed polarity compared to SMA connectors. In RP-SMA connectors, the male has external threads and a center hole (female pin), and the female has internal threads and a center pin (male pin).  SMA stands for Subminiature version A. It is a type of coaxial Radio Frequency connector.
• RP-TNC (Reverse Polarity TNC): These connectors also have reversed polarity compared to TNC connectors. The center pin is male in this case. RP-TNC connectors are found in enterprise-grade WiFi equipment. TNC stands for Threaded Neil Concelman connector, which is a threaded medium size RF connector.
• N Style Connector: This is a threaded RF connector used for connecting coaxial cables in RF applications. Due to its threaded coupling mechanism, it is more secure and reliable in high vibrations environments. They are widely used in outdoor and industrial settings due to their robustness and weatherproofing capabilities.

Beamwidth

Beamwidth is the angular separation between the points in the main lobe where the signal strength drops by 3dB from its maximum gain. It consists of horizontal beamwidth and vertical beamwidth, which corresponds to the horizontal and vertical angles of the antenna’s radiation pattern. A narrower beamwidth means the antenna focuses its energy more in a specific direction, leading to greater range and better resistance to interference.

Now that we have covered the key parameters of the WiFi antennas, let’s take a look into the different types of WiFi antennas and their specific applications.

Types of WiFi Antennas

There are two main types of antennas used in our daily lives. One is omnidirectional and another one is directional. Let’s take a detailed look on each one.

Types	Directivity	Peak Gain	Installation
Panel Antenna	Directional	20dBi	Outdoor
Yagi Antenna	Directional	16dBi	Outdoor
Sector Antenna	Directional	19dBi	Outdoor
Parabolic Grid Antenna	Directional	24dBi	Outdoor
Parabolic Dish Antenna	Directional	34dBi	Outdoor
Fiberglass Antenna	Omni-directional	12dBi	Outdoor
Dipole Antenna	Omni-directional	5-7dBi	Indoor
Ceiling Mount Antenna	Omni-directional	5-7dBi	Indoor
Magnetic Mount Antenna	Omni-directional	5-7dBi	in/outdoor

Omnidirectional

Omnidirectional WiFi antennas are designed to radiate signals in a 360-degree pattern, providing good coverage in all directions, much like an incandescent light bulb illuminates a room. They can also collect signals from all directions. However, these may have a shorter range than directional antennas. Omnidirectional antennas vary greatly in size and shape dramatically. These can be extremely small chip antennas that mount directly onto a PCB and are measured in millimeters. They are commonly used in indoors and outdoors.

Now, Let’s explore the different types of omnidirectional antennas in detail, including fiberglass, dipole, ceiling mount, magnetic mount and patch antennas.

Fiberglass antennas: These are the most popular kind of antennas, made from fiber glass material. They are fiberglass poles, wrapped with copper vibrator and coated with protective material. The antenna shell is glass fiber reinforced plastic, and the antenna coil for fiberglass antenna is typically located at the top of the antenna.

The Fiberglass antenna uses high temperature and high-pressure film pressure technology. It is characterized by no deformation, waterproof, windproof, heat resistance, and strong sealing. These antennas are widely used in fields such as electricity, rail transportation, ocean and maritime applications, energy, transport, infrastructure, electric vehicles, construction technology and many others.

These antennas are known for their durability and long lifespan, often exceeding 15 years. Since they are made from non-metallic composite materials, they are more resistant to corrosion from acids, alkalis, and salts. The structural design, which include multiple vertical and ring rib structures, allows these antennas to withstand harsh weather conditions. Additionally, by incorporating aluminum mesh in the reflective surface, they enhance wave reflection and offer protection from environmental factors. However, fiberglass antennas also have some drawbacks. Changes in environment can cause distortion. Since these antennas are made of fiber glasses, they can age more quickly in higher temperature environments. Some fiber glass materials contain carbon, which can affect the conductivity, and lead to antenna malfunctions.

Dipole antenna: Dipole antennas are basic type of antennas consisting of two conductive elements, and a feedline. As current flows via the feedline the antenna radiates electromagnetic energy at specific frequency. These antennas typically have larger bandwidths, which allow them to support muti-frequency communications.

They offer the following advantages,

• Simple structural design, helping to control costs.
• Wide range of applications, including, routers and mobile devices.
• Since they have strong directivity, they help to control the direction of signal transmission and reception.
• Balanced signal reception.
• Available in various forms such as basic, folded and half wave dipole.

We discussed about the advantages of dipole antennas now let’s check the disadvantages of them.

• To find the best reception point we need to try various combinations of pole placements.
• Difficult to manage outdoor when the size is increases.

If we look at the applications, they are used in WiFi 6/6E/7 antennas, 4G/ 5G LTE cellular antennas, Industrial scientific and medical antennas, and GNSS and GPS antennas.

Ceiling Mount Antenna: It is a device installed on the ceiling to optimize wireless signal. They provide 360-degree coverage and enhance the strength and reliability of the WiFi signals. The use of omni ceiling antennas can help to eliminate dead zones and improve signal quality. By providing the consistent connectivity they ensure the users stay connected to the internet.

Let look at the advantages of ceiling mount antennas,

• They are positioned at a higher elevation, which allows them to provide better signal coverage compare to other types.
• They are more visually appealing.
• Since they are positioned in ceiling they are often away from potential sources of interferences.
• Easy to install.

Let’s look at the disadvantages of the ceiling mounted antennas.

• They may have limited range compared to other antennas.
• Once a ceiling mount antenna is installed, after that it is very challenging to adjust by us.
• Another noticeable constraint is the cost of antenna is bit higher than other types.

Magnetic mount antenna: As its name says itself it can hold the antenna firmly using strong magnets. This makes them for both fixed as well as mobile installations. Furthermore, these magnetic antennas are proper for vehicles, electronic enclosures, and some temporary communication systems.

They offer the following advantages,

• They are widely used in applications where mobility and flexibility are key.
• These mounts allow for secure, easily removable positioning, making them ideal for vehicles and temporary setups.
• For example, GPS antennas on vehicles, CB radios, Emergency service vehicles are using these antennas.

Here are some common constrains of them are,

• Poor signal quality due to insufficient surface contact.
• High VSWR readings.

But with careful tuning and proper techniques you can achieve excellent performance of this.

Next let’s take a look at directional antennas, which focus signals in specific directions to a longer-range communication.

Directional Antennas

Directional antenna is a special type of antenna that works by focusing signals on a particular direction. Here the power of the antenna is more focused in a given direction, so able to send and receive signals to much farther distance. Unlike omnidirectional antennas, directional antennas have a small coverage area.

Now, Let’s explore the different types of directional antennas in detail, including panel antenna, Yagi antenna, sector antenna, parabolic grid/dish antenna.

Panel antenna: A panel antenna is a type of directional antenna which consist of a dipole placed in front of a flat-panel reflector. They are typically rectangular in shape and flat, designed to provide focused beam of radio waves in a specific direction. This narrow beamwidth helps to minimize interface from other signals. The rectangular shape is helped to increase the gain. They are used in point-to-point communication systems. They are often used in wireless backhaul links, which connect two or more network nodes. In addition, they are also used in point-to-multipoint systems. For instance, they are used in wireless access points, which provide internet connectivity to multiple devices within a specific area.

If we look at the advantages of Panel antennas,

• Versatile for stationary and mobile applications.
• Low profile, streamlined design.
• Broader beamwidth.
• Operates at ultra-high frequencies.

But they also have these disadvantages,

• Limited range.
• Lower gain compared to other directional antennas.
• Higher complexity in designing and maintaining are the major constrains of Panel antennas.

Yagi antenna: It is a directional antenna known for its focused signal and high gain. It consists of a central dipole element, which acts as the main source, and several parasitic elements arranged along its length. These parasitic elements re-radiate signals slightly out of phase with the main element, which helps to strengthen the signal in one direction. This makes the Yagi antennas ideal for several applications like radio and TV reception, long-range signal reception and wireless communication.

If we look the advantages of yagi antennas,

• They are highly directional.
• Easy to build
• Cost effective.
• They provide strong signal gain.

However, they also have these disadvantages,

• They have limited bandwidth and frequency range.
• Higher gain models can be quite long.

Sector antenna: A sector antenna is a directional antenna which provides focused coverage in a defined area. Its design includes multiple antenna elements in an arranged manner. Because to create a wide horizontal and narrow vertical radiation pattern. This pattern is very necessary to minimize interference and improve signal quality.

If we look at the advantageous of them,

• Main advantage is their directional coverage.
• They also offer a high scalability.
• Another advantage of sector antennas is cost effective and they are easy to install.

However, a disadvantage of using sector antennas is that more wireless interfaces are needed and that interference can be a problem.

A point-to-point connection needs an antenna which directs all the radio frequency (RF) energy into one direction. The limiting factor for this antenna is mainly its size. High gain antennas reduce the chance of interference to other nodes or to the other antennas of the same node but are often quite large in size.

Parabolic grid/ dish antennas: A parabolic dish antenna is a high precision device that uses a parabolic reflector to focus radio waves onto a specific point. This structure enables it to receive and send signals with high efficiency. When radio waves hit the disc, they are reflected towards the focal point. The shape of the disc is designed according to this manner. Parabolic antennas commonly used in satellite dishes, wireless communication systems, and radar systems.  

When we talk about the advantages,

• They can achieve high gain due to their ability to focus electromagnetic energy into a narrow beam, which makes them ideal for long-distance communication.
• They have a highly directional beam, which minimizes the interference from unwanted sources.
• Also, it can be used both as a transmitting antenna and a receiving antenna due to the principle of reciprocity.

However, they have several cons,

• They can be expensive to manufacture and purchase.
• They only have a limited area of coverage.
• Parabolic antennas need to be precisely aligned and aimed at the desired source.

Patch antenna: It is a popular choice for RFID reader applications. Named for its patch design. It consists of a metal patch suspended over ground plane, with key components like radiating patch, dielectric substrate, ground plane and feeding mechanism.

Let’s look at the advantages of the Patch antennas.

• They are compact in size.
• low-profile.
• Cost Effective.

 However, they also have some limitations.

• They have a lower efficiency, due to dielectric and conductor losses. It reduces the gain of the antenna.
• Additionally, they have limited power handling capabilities. This is making them less ideal for high power application.

Up to now we have explored some kind of basics of WiFi antennas, their key parameters and types. Let’s move on to the comparison between external and internal WiFi antennas.

External and Internal WiFi antennas

WiFi antennas come in two main configurations: internal and external, each with its own advantages and use-scenarios. First let’s look at the internal WiFi antennas. These WiFi antennas are built into device such as routers, laptops, and mobiles. Internal WiFi antennas cannot be attached or detached from the device, since these antennas are embedded within the device’s casing. These types of antennas are designed to save space and maintain a good appearance for the product. While they can be less powerful than some external antennas, technology advancements allow these antennas to give a good performance. Internal WiFi antennas are commonly used in smart TVs, IoT devices and some of the consumer electronics. One limitation of these antennas is that they can be affected by their casing. There are several types of internal WiFi antennas, each designed to serve different tasks. Printed circuit board (PCB) antennas are directly embedded into the device, which offers a cost effective and compact solution for the IoT devices and mobiles. Diversity antennas use multiple antennas, which are helpful to reduce signal disturbance in some challenging environments. As we already see, dipole antennas used internally, provide a balanced omnidirectional coverage.

On the other hand, External WiFi antennas are devices designed to enhance the signal strength and range of a WiFi network which can be mounted outside the device. External antennas can be added or replaced to improve connectivity. Let’s look at some key features and benefits of external WiFi antennas. They have the ability to extend the coverage area of the WiFi network. These antennas are helpful to reduce dead spots. External antennas also come in different types, including Directional and Omnidirectional. Many external antennas are adjustable and rotatable. They are used in variety of devices, including routers, access points and WiFi adaptors. We can mount them on walls, ceilings and desks.  Overall external WiFi antennas are practical solution for improving wireless connectivity.

Both internal and external WiFi antennas offer distinct pros and cons and serve different purposes. Understanding the difference between them helps you to choose the best option for a good connection. Now let’s take a look about Multi-polarized MIMO WiFi Antennas.

Multi-polarized MIMO WiFi Antenna

Before looking into MIMO antennas let’s take a look at the polarization. Imagine a radio wave moving in the air like a series of ripples moving through water. If these ripples move up and down, we call it vertical polarization, if they move side to side, we can call it horizontal polarization. So, for antennas to pick up signals efficiently, their polarization needs to match with the signal. That’s where multiple-input and multiple-output (MIMO) antennas are helpful. They use multiple antennas to handle multiple signal paths simultaneously. With the help of multiple transmitter and receivers, MIMO antennas enables devices to send and receive data more efficiently. If we talk about MIMO antennas we also have to check about the SISO (single input, single output) antennas. SISO antennas just have one transmitter and receiver. It can only receive and send data one at a time. This can limit the speed and reliability.  If you want best data rates, MIMO WiFi antennas are always the best choice.

Conclusion

To wrap it up, if you want to optimize your network’s performance, then you need to choose a right WiFi antenna to the network. Different types of antennas, serve different purposes. Internal antennas are good for day today use in small devices and external antennas give a best coverage and flexibility for larger spaces. If you need a faster reliable connection, MIMO antennas are the best choice. By picking the right WiFi antenna for your WiFi network, and for your needs, you can improve your WiFi signal coverage, reduce the outside interference and enjoy a smoother, more stable connection.