This is a placeholder topic for "Nagoya NA-773 antenna (Seeed Studio) " comments.
The Nagoya NA-773 antenna is a 50 ohm, SMA male connector telescopic antenna designed for handheld devices operating in 144MHz and 430MHz ranges, and offers…
Read moreI’m looking for an antenna to boost the communication distance of my LoRa SX1278 modules (433MHz). Would the Nagoya NA-773 antenna (Seeed Studio) be suitable?
Hi Meg,
This Nagoya NA-773 antenna is advertised as being “usable for all frequencies under 1 GHz”, although personally, I feel that’s quite a claim, as telescopic monopole antennas such as this are generally designed to perform in one or a few tight frequency bands most effectively.
(This is for a few reasons, but most simply due to the wavelength versus antenna dimensions, and antenna material/connection-types/etc. there are some other members on this forum who’d be able to explain why in much more depth than me, long story short, in the case of radios, there is no such thing as one-size-fits-all for anything)
In this case, the NA-773 seems to be rated for bands around the 144MHz and 430MHz mark, given it is a fairly standard choice of antenna for the various RF Explorers.
Anyway, to calculate the communication distance, or range, of a combination of transceiver and antenna pair, you need to perform a couple of calculations to get an estimate:
First off, you need to estimate the Equivalent Isotopically Radiated Power or EIRP. You can get this by simply adding the power of the transmitter and gain of the antenna (in dBm and dBi respectively) In this case, the antenna should sit around 2.1dBi
Then, the power at your receiver needs to be estimated in a similar way. You take the EIRP of the transmitted signal you just got, add your receiving antenna’s gain (in this case, likely 2.1dBi again if your setup is symmetrical), then subtract the path loss (which is the ‘loosest’ part of estimating radio range as many environmental factors affect this). The rule of thumb for km and MHz is generally (log base-10):
Path Loss ~= 20 * ( log(distance) + log(frequency in MHz)) - 147.55
Once you’ve got that result (Received Power = EIRP + Receiver Antenna Gain - Path Loss), that’s an estimate for your received power. As long as it is reasonably higher than the sensitivity of the receiver on the LoRa SX1278 you should be able to receive the transmissions (albeit ignoring noise and several other factors I haven’t mentioned here). Performing all of these calculations fairly conservatively, you should be able to get a rough idea for how much further the NA-773 would extend your signal over the antenna you’ve currently got on your SX1278.
