Dual Band Wi-Fi Antennas with RP-SMA connector
Dual-band WiFi Antennas with RP-SMA Antennas:
Dual-band RP-SMA antennas are a type of antenna that is resonant at two frequencies, usually 2.4 GHz and 5GHz, and use a reverse polarity SMA cable or RP-SMA connector as their primary point of mechanical and electrical connection. Dual-frequency antennas are diverse with a broad range of designs suited to specific wireless networking applications, in particular several key 802.11 WiFi standards that facilitate wireless networking at both the standard 2.4 GHz frequency and 5 GHz. They can operate at each of the frequencies individually or simultaneously depending on the antenna’s design and operation.
Key types of dual-band antennas with RP-SMA connector.
[A] Omnidirectional RP SMA dual-band antennas provide 360-degree coverage around the antenna's vertical axis. They may be used indoors, for broad coverage, or outdoors in part of a star topology WiFi network.
[B] Directional dual-band antennas with RP-SMA connector focus radio frequency energy in a specific direction for robust connectivity with increased gain that is ideal for setting up point to point wireless links.
[C] Dual-band puck WiFi antennas are omnidirectional antennas that have a radome that is shaped like a hockey puck. They are a low-profile choice that is ideal for through-hole mounting on ceilings, walls, or vehicle roofs.
[D] Dual-band panel WiFi antennas are low-profile directional antennas that can be wall-mounted to deliver WiFi coverage at either 2.4 GHz or 5 GHz in a specific area.
[E] Articulating dipole dual-band antennas with RP-SMA connectors are a common choice for replacement antennas for routers and access points as they can be more precisely positioned for optimal coverage and performance. They are omnidirectional antennas.
[F] Co-linear dual-band WiFi antennas house their radiating elements in a weatherproof fiberglass radome, making them ideal for outdoor waterproofing installation at height.
The section of dual-band RP-SMA antennas provided above are manufactured to the highest quality standards and their materials and fabrication are compliant with RoHS and 3TG conflict minerals legislation including The Conflict Minerals Regulation and Section 1502 of the Dodd-Frank Act.
How do dual-band antennas work?
Dual-frequency antennas are capable of being sensitive to two distinct frequencies because they usually consist of at least two quarter-wavelength monopole or Hertzian dipole elements, which are of different lengths and are housed within a single radome. Other dual-band antenna designs use PCB antennas or frankly stack two separate antennas together each with a coaxial line. In a dual-band antenna, each element will resonate at its fundamental frequency. The thickness of the copper wire used within the antenna wavelength also influences the bandwidth of the antenna, making sure that the target frequencies are fully covered and the dual-band antenna delivers consistent performance at both frequencies.
The 2.4 and 5 GHz frequency bands
- The 2.4 GHz frequency band spans 2400 MHz to 2485 MHz. It is commonly subdivided into, depending on geographic region, 11 to 14 sub-bands of 20 MHz widths known as channels.
- The 5 GHz frequency band ranges from 5.15 GHz to 5.35 GHz and 5.725 GHz to 5.825 GHz. It is further subdivided into 20 MHz to 160 MHz channels for wireless data transfer.
Both frequency bands are unlicensed and originally designated for Industrial, Scientific and Medical purposes by the International Telecommunications Union. These uses have been largely overtaken by wireless networking and in particular WiFi as we explore further on.
The RP-SMA connector is a miniature radio frequency connector ( diameter 0.312 inches / 7.9 millimeters) commonly used in consumer wireless networking hardware and so will make the above dual-frequency WiFi antennas compatible with a broad range of products. RP stands for reverse polarity and denotes this connector as a variant of the standard SMA, or Sub-Miniature version A connector which predominates more in cellular networking. Both are threaded brass connectors, with 50 Ohm impedance and frequency range of DC to 18 GHz, but the RP-SMA connector is named because of a deliberate reversal of the inner mating interface of the connector.
- The male RP-SMA connector has 36 thread per inch internalized threads within a body that carries a hex nut for tightening the mated connection. Within the male connector, the mating interface carries a receptacle rather than the pin that is found on the standard SMA connector.
- The female RP-SMA connector has externalized threads and carries a pin as its inner conductor, rather than the receptacle that is found on the female SMA connector.
The reversal of the inner mating interfaces was undertaken to prevent powerful industry-standard antennas from being connected to consumer wireless devices. This reversal was mandated by the Federal Communications Commission, but the effect of this strategy has been eroded by the widespread availability of these connectors. RP-SMA and SMA connectors may be able to make a physical connection but they are unable to form an electrical one.
The RP-SMA connector forms a robust screw-coupled connection that is weatherproof and resilient against shocks and vibrations. It is rated for over 500 mating cycles meaning RP-SMA antennas can be connected and disconnected with confidence.
Why are dual-band reverse polarity SMA antennas important?
Dual-band antennas are a convenient solution for wireless networking at both 2.4 and 5 GHz. They are chiefly used as WiFi antennas for WiFi routers and access points. 2.4 GHz and 5 GHz frequency bands have different characteristics, strengths, and weaknesses.
Signal propagation, coverage, and use of the 2.4 GHz frequency band
The 2.4 GHz ISM frequency band is routinely used for wireless networking, Aside from WiFi, 2.4 GHz frequency applications include personal area and mesh networking solutions like Bluetooth and ZigBee as well as a variety of unlicensed products like baby monitors and cordless phones.
The properties of this portion of the radio frequency spectrum make it advantageous for both indoor and outdoor wireless connectivity.
As the lower of the two frequencies, 2.4 GHz transmissions can achieve longer ranges. This is because lower frequencies on the RF spectrum lose less energy and are absorbed less as they are propagated.
With a wavelength of 13 centimeters, the 2.4 GHz band has distinct transmission, reflection, and absorption characteristics that mean that it achieves good coverage and penetration, especially in indoor settings. In buildings, 2.4 GHz signals can penetrate load-bearing materials, insulation, and cover materials like plaster and chipboards. As they pass through solid objects less of the RF energy is absorbed than at 5 GHz. This means that WiFi and other 2.4 GHz signals can provide excellent multi-room coverage, with a waveform that can pass through many walls. As expected, metal and dense concrete reflect a significant proportion of transmitted signals and should be avoided when sitting antennas.
Less available bandwidth at this frequency is a notable disadvantage of this band as it is often used by a lot of wireless traffic and can be susceptible to slower data rates and frank interference. The use of a dual-band WiFi antenna is a key solution for ameliorating this common problem.
Signal propagation, coverage, and use of the 5 GHz frequency band
The 5 GHz frequency band is composed of 4 different sub-bands. It offers a far greater bandwidth with up to nineteen non-overlapping 20MHz channels between 5.15 and 5.85 GHz. This frequency band has a much shorter wavelength (6 centimeters), around half that of 2.4 GHz, and is higher energy. It is capable of high-speed data transmission via narrow beams that can be accurately directed. This makes it advantageous for indoor WiFi networking. The four bands...
- A upper (indoor) 5.150 GHz to 5.250 GHz
- A lower (indoor) 5.250 GHz to 5.350 GHz
- B (indoor or outdoor) 5470 GHz to 5725 GHz
- C (outdoor) 5735 GHz to 5850 GHz
...support both indoor and outdoor networking, with an increased limit on output power provided for certain bands to increase their range (to several kilometers) for outdoor point to point wireless links.
It is a far less congested frequency than 2.4 GHz as it has fewer commercial and consumer applications. However, 5 GHz signals are easily reflected, refracted, and absorbed as they propagate. This means that the coverage that can be attained by 5 GHz signal transmissions is drastically reduced compared to 2.4 GHz, though the line of sight between antennas and devices will improve it to an extent. 5 GHz is only minimally absorbed by water or damp objects but has low penetration of solid objects and structures. Its inability to penetrate walls also limits its use indoors.
Enjoy the best of both works with a quality dual-frequency antenna
By connecting a dual-frequency antenna, to a compatible router or access point, users immediately increase the bandwidth available for dual-band WiFi networking. Also, dual-band antennas have the following key benefits:
- Dual-band RP SMA antennas support stable wireless connections
By having the option to operate at either 2.4 GHz or 5 GHz users can benefit from consistent and continual service as if delay or interference is encountered at one frequency, the alternate frequency can be used for data transfer. Most dual-band routers and access points are designed to automatically switch between the two frequencies so that the best quality signal is always experienced.
- Dual-band WiFi antennas mean that you can install or mount one antenna to harness both frequencies
If you are installing roof, wall, or through-hole mounted antennas for long-term use, a dual-band option means that you will be able to use the antenna for 5 GHz networking, even if you are only using 2.4 GHz WiFi at present. It also saves the time and expense of mounting two antennas in a particular location.
- Using a dual-band 2.4 GHz / 5 GHz antenna increases capacity of a network for data transfer
Having the 5 GHz wireless channels available on top of the 11 to 14 standard means that there is significantly greater bandwidth available. This is especially important for high-throughput wireless links that can utilize the speed and space available at the higher 5 GHz frequency while more mundane digital traffic can be transferred at 2.4 GHz.
- With a dual-band RP-SMA antenna, you procure the benefits of each frequency
Using the 802.11 protocols outlined below to enable you to use WiFi at both frequencies for a better end-user experience. This means that your network can have the range and penetration of 2.4 GHz along with the speed and capacity provided at 5 GHz.
- A dual-band antenna will help you cut down on interference
With dual-band antennas, you will be able to take advantage of the maximum number of non-overlapping channels which means the potential for interference is much less. By using the 5 GHz frequency band, the traffic from other networks and appliances and increased collisions experienced at 2.4 GHz are effectively bypassed.
- Using a dual-band antenna may increase the number of devices you can use on your network
Having 5 GHz WiFi networking available means that you can integrate newer devices that are capable of sending and receiving data at a higher frequency as well as the standard 2.4 GHz. Many versions of WiFi offer backward compatibility providing the ability to use 2.4 GHz-only and 5 GHz-capable hardware together, or as complementary technologies.
802.11 protocols that specify dual-band WiFi networking
The proprietary wireless networking standards produced by the WiFi Alliance detail the key versions of WiFi that can support dual-frequency networking. These versions are:
- 802.11a also known as WiFi 2
- 802.11n known as WiFi 4
- 802.11ac also known as WiFi 5
Dual-band antennas for 802.11a WiFi networks
WiFi 2 (802.11a) was the first version to take advantage of 5 GHz networking and is capable of operating interference-free alongside 2.4 GHz equipment. It is for 5 GHz only and not interchangeable with older, 2.4 GHz technologies (802.11b/g and 802.11a). It delivers data rates of up to 54 Mbps with the right WiFi antenna across up to 19 non-overlapping channels.
802.11a uses Orthogonal Frequency-Division Multiplexing (OFDM) as its primary form of encoding data onto the carrier signal your dual-band antenna will use. The 5 GHz frequency band has ample capacity to support this form of wide-band data transfer that involves sending data across multiple orthogonally aligned and overlapping sub-channels for improved spectral efficiency.
Dual-band antennas for 802.11n WiFi networking
802.11n is usually recognized as the version of WiFi that is notable for its use of multiple antennas in a spatial diversity arrangement. Using Multiple Input, Multiple Output MIMO, WiFi 4 can support high throughput extensions at either 2.4 or 5 GHz and achieve data rates of up to 600 Mbps if 4 spatial streams are generated by the connectivity of the multiple antennas are used. The use of OFDM additionally enhances speeds. It offers backward compatibility with 802.11b, 802.11g, and 802.11a, meaning that WiFi is an advantageous version for dual-band WiFi networks where legacy technology may still be in use. The purchase of multiple dual-band antennas means that all the performance benefits of 802.11 n can be experienced.
WiFi 5 networks use dual-band antennas
802.11ac pushes the speed, throughput, and capacity limits of WiFi with a 5GHz version that uses MIMO-based networking. It is capable of delivering multiple spatial streams with broad bandwidth (channel sizes of up to 160 MHz) and the ability for up to 8 devices to use the network at maximum speed (up to 1 Gbit/sec) simultaneously. This enterprise-level version of WiFi requires up to 8 antennas to deliver its specified performance, with a variety of Phase Shift Keying modulation techniques used to encode data on the carrier wave.
Frequently asked questions
What is a non-overlapping WiFi channel and why is it important?
At both 2.4 GHz and 5 GHz, the available portion of the spectrum is sub-divided into several numbered channels. They are used as distinct pathways for sending and receiving data within the frequency band. The standard portioning of bandwidth within the channels produces overlapping of adjacent channels. This overlapping means that if routers or devices use two adjacent channels for simultaneous transmissions, interference can occur with a reduction in speed. Within both frequency bands, some channels can be used simultaneously without interference because they do not overlap with each other. At 2.4 GHz these are:
- Channel 1
- Channel 6
- Channel 11
There are 19 further non-overlapping channels available at 5 GHz. Channel planning and selection is one of the simplest ways of improving the performance of your WiFi network. The WiFi settings can be altered to ensure that the AP, router, or devices specifically use the non-overlapping channels.
Is a dual-band antenna better than individual 2.4 GHz and 5 GHz antennas?
A single band antenna is specifically designed and optimized for its fundamental frequency which means that they are likely to outperform a unit that is serving two frequencies simultaneously. However, dual-band WiFi antennas aren't to be underestimated. It all comes down to the design of the antenna and the quality of its fabrication. A properly designed antenna delivers a good impedance match for each band with proper phasing and resonance in each band rather than being centered between the two frequencies. As mentioned above, the key advantages of a dual-band antenna are the space and cost savings gained on using a single antenna for two frequencies. The performance of a dual-band antenna will also depend on how the router is configured. Plugging a dual-band antenna into a port that receives only a single frequency will only lead to the networking performance associated with that frequency. Also, WiFi routers that do not utilize an 802.11 protocol that facilitates 5 GHz connectivity will be unable to use the 5 GHz part of a dual-band WiFi antenna.
Dual-band antennas are critical to getting the maximum performance out of WiFi-based networking as they provide the ability to utilize the key 5 GHz WiFi protocols as well as standard 2.4 GHz networking. Diverse designs, characteristics, and gains of these dual-band RP-SMA antennas mean that they can be used effectively for high-throughput wireless networking in both domestic and enterprise settings. The RP-SMA connector makes connecting and mounting these dual-band antennas simple, convenient, and secure.