Log-periodic antenna 300–6000 MHz

The 300–6000 MHz log-periodic antenna spans a twenty-to-one frequency range: 300 MHz to 6 GHz on a single directional antenna, with no retuning and no swapping for each job. This is the larger model in the range — it sees what the 530–6000 MHz version cannot.

What those 230 MHz at the bottom buy you

The gap between 300 and 530 MHz looks small until you look at what sits inside it. This is one of the busiest stretches of spectrum there is:

• 433 MHz ISM — telemetry, LoRa, remote controls, sensors
• 430–440 MHz — the amateur UHF band
• 446 MHz PMR — handheld radios
• 300–400 MHz — service and departmental channels
• 470–530 MHz — the lower DVB-T television channels

If none of those frequencies matter to your work, the compact 530–6000 MHz model is enough and costs half as much. If even one of them does, this antenna has no substitute — and that is what you are paying for.

Why it is bigger

The lowest frequency of a log-periodic antenna is set by its longest element: roughly half a wavelength. At 300 MHz the wavelength is a metre, so the element comes out at about half of that — hence the 430 mm width at the bottom of the board and the 500 mm height. For comparison, the 530–6000 MHz model gets by on 260 mm, because its wavelength is nearly half as long.

That is physics, not marketing: an antenna that works from 300 MHz cannot be small. The board area here is roughly three times larger, which is where the price difference comes from.

Direction instead of power

The antenna listens where it points and hears markedly less from the sides and behind. In crowded spectrum that often decides more than gain: a strong neighbouring transmitter falls outside the main lobe and stops swamping the receiver. Rotating the antenna also gives you the direction to a source — a basic move in radio monitoring and transmitter hunting.

Who it suits

• radio monitoring and direction finding across everything from UHF to 6 GHz
• SDR setups: one antenna for every scanning job
• work with 433 MHz telemetry and control links
• DVB-T reception alongside the rest of the spectrum
• fixed spectrum-monitoring posts
• laboratory measurements and RF equipment testing

Construction

The antenna is built on a printed circuit board with a log-periodic conductor structure, each section responsible for its own part of the band. Printing delivers repeatability — the next unit performs like the last one, with no hand-picked elements.

The board carries an RF connector area and mounting holes for a bracket, an enclosure or your own product. Do account for the size: 500 × 430 mm is a fixed or mast-mounted format; for a backpack the smaller model is the easier companion.

Measurements

We measured the radiation pattern in an anechoic chamber and published it in full: the report with 2D and 3D plots opens straight in the browser and can be rotated and zoomed. What we show is our own measurement, not a figure from someone else's datasheet.

If the lower frequencies are not needed, compare it with the 530–6000 MHz log-periodic antenna — smaller and half the price. Not sure which of the two you need? Send us the list of frequencies you work with and we will advise.