The antenna amplifier presented below is extremely simple to manufacture. It has good gain, low noise and low current consumption. Plus a very wide range of work. Yes, it is also miniature in size, thanks to which it can be embedded anywhere.
Where can I use a universal antenna amplifier?
Yes, almost anywhere in the wide range of 50 MHz - 4000 MHz.
- - As a TV antenna signal amplifier for receiving both digital and analogue channels.
- - As an antenna amplifier for an FM receiver.
- - etc.
This applies to domestic use, but in the amateur radio field there are much more applications.
Antenna amplifier characteristics
- 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 to be excellent. The low current consumption is fully justified.
The microcircuit also perfectly withstands high-frequency overloads without loss of characteristics.
Making an antenna amplifier
Scheme
The circuit uses an RFMD SPF5043Z microcircuit, which can be purchased at - AliExpress.
In fact, the entire circuit is an amplifier microcircuit and a filter for its power supply.
Amplifier board
The board can be made from foil PCB, even without etching, as I did.
We take two-sided foil-coated PCB and cut out a rectangle measuring approximately 15x20 mm.
Then, using a permanent marker, draw the layout along the ruler.
And then you want to etch, or you want to cut out 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 shielding the substrate.
Setup and testing
No adjustment is required; you can, of course, measure the input voltage, which should be within 3.3 V and the current consumption is approximately 25 mA. Also, if you operate in the range above 1 GHz, you may need to match 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 level.
It will be very good if you place the board in a shielded case, like this.
A board of a ready-made amplifier can be purchased at AliExpress, but it costs several times more than the microcircuit separately. So it’s better to get confused, it seems to me.
Schema addition
To power the circuit, a voltage of 3.3 V is required. This is not entirely convenient, for example, if you use the amplifier in a car with an on-board voltage of 12 V.
For these purposes, you can introduce a stabilizer into the circuit.
Connecting the amplifier to the antenna
In terms of 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 DC-switched, that is, you need to use a loop or frame vibrator. Antenna type "Biquadrat"would be a great option.
