Bi-Loop instead of biqod (1296MHz)

[eco32 27]

I am thinking of using bi-loop instead of biquad, I use matlab on a daily basis, and I have not yet managed to make a model, I am currently unable to check

1) Bi-Loop is mechanically simpler to make, tune and correction.

What else, what profit can it give.

In publication about this antenna for a 2,45GHz:

"The simulation results showed that the best parameters value are 14.95 mm of loops radius, 1.15 mm of links radius, and 15.57 mm of reflector gap. In these parameters, the antenna had a characteristic value of return loss -36.65 dB, bandwidth 354 MHz"

IMG_1496.webp

[Admin 2546]

,,,it is also possible like this, with circular dipole...

 

[Harry36 140]

7 hours ago, Admin said:

,,,it is also possible like this, circular dipole...

It's not dipole, this is biguad + balun )

Edited September 16, 2022 by Harry36

[Admin 2546]

,,,biloop, it"s two circular dipole...!!!

[Harry36 140]

On 15.09.2022 at 1:35 PM, eco32 said:

What else, what profit can it give.

 

 

Figure 2 in the quote shows the dimensions of the antenna for LTE800 band (min swr~ 850 MHz), it is made in the form of two antenna sheets on different sides of FR4. the dimensions match the simulation quite well.

 

In order to make a similar antenna for a frequency of 1296 MHz, you need to reduce the dimensions by a factor of 1.52 dimensions.

 

The antenna has a fairly low gain of ~7.2 dBi. This is due to the minimum size of the reflector. By increasing the reflector to 250x250 mm, you can increase the antenna gain to 9.5 dBi at the same time, if you do not change other dimensions, the SWR also increases to a value of 1.1. tFR4=1mm, tCopper=0.018, H=28.4.

Antenna connection is shown in fig. 1 quota is performed without balancing, this is a wrong connection. The cable must be soldered from the side of the web of one of the antennas (upper or lower) and brought along the arc of a circle to the middle of the frame (circle), then lowered onto the reflector, where to install the connector. Cable use RG-316.

FR4 is a rather unstable material and antennas made from it very often fall outside the calculated range. for home production without appliances, it is not entirely suitable. it may be easier to make an antenna out of metal. For example, by type BDM. reflector and two disks. this will give a fairly wide bandwidth at a very low SWR and will forgive manufacturing errors even with a hand tool.

 

or stack 2x2

or dipole from metal can dia=66.3 mm

 

[eco32 27]

 in the simulation I achieved 14dBi. This brim is shallower than the simulation assumes, it could be 11.3 dBi. The antenna is very effective. I'm thinking of replacing the quadrates with loops. I'm thinking of a similar implementation as in the attached pictures, not laminate.

@Harry36 Thank you for the clarification.

With this antenna I am receiving ham radio beacon beacon SR6 LHZ 1296.830 with level -80dBm - distance 111 km, power 1W

My aim is to increase the gain of a single biquad. maybe changing the shape or geometry will help.

That is my antenna:

[eco32 27]

"What else, what profit can it give."

@Harry36 :

I am curious with a bi-loop "in the box" I will be able to get more gain than a biquad, smaller in size, or a better shaped beam

I don't have the tool to check this, Matlab antenna toolbox has some limitation.

box diameters: 40cmx27cmx20cm +/- 1cm