The more I learn about the modern elemental base, the more I am surprised at how easy it is now to make electronic devices that you could only dream of before. For example, the antenna amplifier in question has an operating frequency range from 50 MHz to 4000 MHz. Yes, almost 4 GHz! At the time of my youth, one could just dream of such a thing, and now such an amplifier on a tiny microcircuit can even be assembled by a novice radio amateur. And not having experience with super high-frequency circuitry.
The antenna amplifier below is extremely easy to manufacture. It has good gain, low noise and low current consumption. Plus a very wide range of work. Yes, also a miniature size, thanks to which it can be embedded anywhere.
Where can I use a universal antenna amplifier?
Yes, almost anywhere in a wide range of 50 MHz - 4000 MHz.
- - As a television antenna signal amplifier for receiving both digital and analogue channels.
- - As an antenna amplifier for an FM receiver.
- - others
This is for domestic use, but in the amateur field of application, much more.
Antenna amplifier specifications
- Operating range: 50 MHz - 4000 MHz.
- Gain: 22.8 dB - 144 MHz, 20.5 dB - 432 MHz, 12.1 dB - 1296 MHz.
- Noise figure: 0.6 dB - 144 MHz, 0.65 dB - 432 MHz, 0.8 dB - 1296 MHz.
- Current consumption is about 25 mA.
More detailed specifications can be found in datasheet SPF5043Z.
The low-noise amplifier has proven itself perfectly. Low current consumption justifies itself.
The chip also withstands high-frequency overloads without loss of performance.
Production of antenna amplifier
The circuit uses a RFMD microchip SPF5043Z, which can be bought at - AliExpress .
In fact, the whole circuit is an amplifier microcircuit and a filter for its power supply.
The circuit board can be made of foil PCB, even without etching, as I did.
We take two-sided foil textolite and cut out a rectangle about 15x20 mm in size.
Then, with a permanent marker, draw the wiring along the ruler.
And then you want to poison, but want to cut the tracks mechanically.
Next, we tin everything with a soldering iron and solder SMD elements of size 0603. We close the bottom side of the foil board to a common wire, thereby screening the substrate.
Tuning and testing
No tincture is required, of course you can measure the input voltage, which should be within 3.3 V and the current consumption is approximately equal to 25 mA. Also, if you work in the range above 1 GHz, then you may need to coordinate the input circuit by reducing the capacitor to 9 pF.
We connect the board to the antenna. The test showed good gain and low noise.
It will be very good if you place the board in a shielded case, such as this.
The board of a ready-made amplifier can be bought at AliExpress, but it costs several times more than a microcircuit separately. So it’s better to get confused as it seems to me.
To power the circuit, a voltage of 3.3 V is required. This is not very convenient, for example, if you use an amplifier in a car with a voltage of 12 V.
For these purposes, you can enter a stabilizer in the circuit.
Connecting an amplifier to an antenna
By location, the amplifier should be located in close proximity to the antenna.
To protect against static and thunderstorms, it is desirable that the antenna be closed by direct current, that is, you need to use a loop or frame vibrator. A Biquadrat antenna would be a great option.