The CPAA-18 is Betso's flagship receiver antenna because of its enhanced receiving performance. Circular polarization, compared to traditional linear polarization, has much better performance in non-line-of-sight situations and mainly in situations, where transmitter antenna can be randomly oriented in the horizontal or vertical position. Additionally the inbuilt, high quality, extremely low noise amplifier, is ideal for situations where long cables with high attenuation have to be compensated or where signal strength is too weak.

Circular Polarization Benefits

The main advantage of a receiver antenna with circular polarization is its orientation independence which is independent of the orientation of the transmitter antenna. In traditional linear polarized systems, when antennas are not aligned, there is a significant link performance degradation, which can lead to link losses or dropouts. On the other hand when a receiver antenna with circular polarization is used, this problem is almost nonexistent. Moreover, the link performance is even better in adverse weather conditions or in environments with a lot of obstructions, which are effects that cause signal polarization displacements.

Ultra Low Noise Onboard Amplifier - 9 to + 18 dB

An inbuilt ultra low noise amplifier allows antenna usage in situations with variable coaxial cable length from the antenna to the receiver device. Higher attenuation of longer cables can be easily compensated by increasing gain, while in situations with very short cables and a strong receiving signal, zero or even negative gain promotes not overshooting the input dynamic range of the receiver. The amplifier can be easily adjusted to any value betwen - 9 and + 18 dB in steps of 1 dB.

Excellent RF parameters

What is unique about the Betso CPAA-18 are it's excellent RF parameters. A voltage Standing Wave Ratio of less than 1.2 ensures great signal power reception. A very high Third-order Intercept Point IP3 >34 dBm provides great linearity, and finally an industry leading ultra low noise amplifier IC with a noise figure of 0.75 dB.

High efficient input filters for removing unwanted RF spectrum

CPAA-18 high efficient input filters help to prevent receiver intermodulation with other sources in the band outside of the main working range of wireless systems like walkie talkies, FM radios, wireless focus systems, WiFi and bluetooth devices, mobile phones, etc. The performace of wireless systems will be better with less dropouts.

Plug in Workability

The preset value of onboard amplifier gain is displayed on the inbuilt seven segment LED display upon power-up and, if required, it keeps displaying for permanent possible readouts. The display also has an automatic brightness setting feature, which adjusts display brightness according to ambient light conditions, avoiding unacceptable situations of the display shining too brightly in dark places or an unreadable gain value in direct sun light. This automatic brightness feature can be disabled by setting the fixed brightness value, or the display can be completely turned off while the amplifier keeps working. In this mode, pressing any button will temporally power on the display for possibility of changing the settings or just for the preset gain readout.

Top Build Quality

The main disadvantage of circular polarized antennas is their size.  The size of the Betso CPAA-18 is minimized through professional RF design with a focus on dimensions, weight and reception performance. The result is a great performing active antenna packed in very reasonable sized case, reinforced by high quality materials put together with top manufacturing processes. The amplifier is made of CNC milled aluminium alloy and is sealed for excellent water resistant performance. Permanent mounting is possible by standard 4x M4 screw holes with a 100mm pitch.


The antenna can be powered externally through coaxial cable from a power source of 5 - 20 V DC. Professional hardware design with best in class integrated circuits results in extremely low power consumption which will be a big plus for the power distribution of your sound cart.


Frequency range

470 MHz to 850 MHz

Input filters attenuation

High below 450 MHz (for example -82dB @ 100 MHz)

Antenna gain

7.5 dB of average gain (peak 8.5 dB)

Antenna directivity


Antenna polarization


Amplifier gain

-9 to 18 dB

Amplifier IC noise

Ultra low noise < 0.75 dB

Antenna VSWR

Excellent < 1.2 (max. 0.8% of received signal power is reflected)

Amplifier IP3

Very high > 34 dBm


Bright blue LED with automatic or manual brightness settings and stand-by mode


External powering 5 - 20 V DC

Current consumption

35 mA *

Mechanic construction

CNC milled, anodized aluminum alloy and ABS highly durable plastic


1/4" and 3/8" threads

Dimensions (h x w x d)

315 x 315 x 110 mm (12.4" x 12.4" x 4.33")


approx. 1.4 kg (3.1 lb.)


Betso - CPAA-18 - Circular Polarized Active Antenna

  • Brand: Betso
  • Product Code: CPAA-18
  • $725.00