Double Bi-quad Antenna Design Calculator

Double bi-quad antenna dimension calculator

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On-line antenna designer. Calculate the required dimensions for a double bi-quad antenna construction for any given frequency. A directional antenna ideally suited for UHF and above frequencies for use with WiFi, UMTS, LORA, mobile phone networks and more.

Enter the required frequency in MHz and the antenna designer will calculate the dimensions of the elements as shown below.

Enter Frequency (MHz)

The dual bi-quad antenna, also known as the 'bow-tie' antenna is a directional antenna ideal for use with LORA applications, mobile phone systems for UMTS, G3, G4, G5 and WiFi equipment. It can be constructed from any common household copper wire 2-2.5mm. The reflective surface can be any conductive material, I have heard that even CD's work as effective reflectors.

Performs really well for WiFi and can be used for both RX and TX purposes. It can be made from any common copper household electrical wire. The thicker the wire, the wider the bandwidth of the antenna from its center frequency.

Frequency calculations are based on radio waves traveling at the speed of light 299 792 458 meters per second.


A: ? mm
B: ? mm
C: ? mm
D: ? mm
E: ? mm


A: ? "
B: ? "
C: ? "
D: ? "
E: ? "

Dual Bi-Quad Antenna
Dual B-Quad Connection

Antenna connection

Dual Bi-Quad Spacing

Element overlap spacing

Above images show a prototype dual bi-quad antenna built for WiFi using this antenna calculator.

With the reflector installed it becomes a directional antenna with more gain. This antenna can be used with vertically and horizontally polarized RF services.

Dual Bi-quad Antenna Design

Note: After receiving several questions about the rear reflector for this antenna, the following:

  • The diagram shown is not to scale.
  • The minimum reflector measurement should be a quarter of a wavelength larger on each side of the antenna than the dimensions of the active antenna element itself. (half wave longer is a bit better, but more has no effect)
  • Purpose of the reflector is to block rf signals from the rear while allowing bounced rf of the reflector to reach the antenna in phase with the directly received rf on the antenna itself. Making it a forward facing unidirectional antenna with a bit of gain.
  • The reflector does not need to be made of a solid metallic material, a great wind catcher outdoors. It can be made with wire mesh, the distance between the mesh should be smaller than a quarter wavelength and not a multiple division of the required frequency wavelength.
  • If you want a bi-directional antenna, receiving from both front and back, the reflector can be ignored and removed completely.