The Road to Better Receiver – Receiver Modules

This is the first post of ‘the road to a better receiver’ series, in which we’re planning to share a story in how to build a better wireless receiver for everyone.

In the first series, we will mainly focus on one of the most important component of wireless receiver, which is the receiver module.

Here the story begins

In case you didn’t know, our 202U receiver, even is still one of the most advanced receivers on today’s market (compared to many standalone RF relay receivers, that sold on eBay or Amazon), is quite an old receiver, which was developed in 2011-2012, almost 5 years ago.

I still remember, during the development of 202U receiver, our main goal is to make a wireless receiver that out-performs most receivers at that time, and with a human friendly interface for easy operation, so we have used many features that are not commonly seen by then, such as superheterodyne receiver modules, dip switch mode switch, universally fit power input range and a very strong enclosure.

At that time (even now), many receivers are still using old style super-regenerative modules, they show a very weak distance compared to ours, for example, using the same transmitter, their distance is somewhere around 50m, while ours can reach as far as 200m (yes, the difference is that much).

Many readers might thought, so if the receiver claims to be superheterodyne modules, it would be alright, it would reach a long range. Unfortunately, this is not true, because there are actually many models superheterodyne modules, and their performance difference is not hard to see.

How we choose receiver module for 202U receiver

We don’t have much experience about superheterodyne module at that time, so the best bet is to source many different modules on market, and do a comparison, to see how they will perform in field, so we went to our local electronics market, which is the biggest electronics market on earth – HuaQiangBei, to buy the receiver modules we need, and we have bought at least 5 different kind of modules to test them out.

They all looks different from outside, but as soon as our engineer check them out, we can see actually some are using the same chip, so we did a little work, and concluded the chips they’re using are SYN470R, SYN480R series from Synoxo (a French company), and a old receiver ic RX3310 from HiMark technology (a Taiwan company, now defunct), and another chip we can’t identify (because the text on it are wiped out)

Although we’re excited to test them out, the result is very disappointing, all receiver modules under test are showing strong near-field blocking (which is not seen on old super-regenerative receivers, but seen on many early time superheterodyne ones), and the testing range are around 50m, or even less, this is worse than ordinary super-regenerative ones.

Although the test results are disappointing, we didn’t give up on finding better receiver module, so we get another newer sample from Princeton Technology’s distributor, at that time, Princeton Technology just acquired HiMark (you can even see RX3310A model at their webpage now), and they just released new products under their own brand, the PT4301 and PT4302 series.

What we test at that time was PT4301, the chip has surprised us by its excellent sensitivity (range) and minimum near-field blocking effect, we can achieve 150m+ range using exactly the same transmitter, which is just perfect, but we don’t need some features on PT4301, so we have finally chosen its sister product, PT4302 as the standard module shipped with our newer receiver, namely 202U, 201U and 204U.

Choosing PT4302 is a optimal choice for us, they are some better performance chips, such as Infineon’s TDK5210 series, but the cost is much higher, and the performance margin is not that much.

And PT4302 is a good choice for us during these years’ production, as it shows superior performance compared to most counterparts on market, and is still performing well.

But we still need to move on…

As you can still see on Princeton Technology’s website, their receiver IC has stayed the same for past 5 years, there are no new products, the same circumstance happens to Infineon and other big players.

5 years without new products, without technology improvement, it just seems not right, especially in electronics world.

When we plan to make our new generation receiver for 2016 and beyond, we know we can’t stay using the same receiver module for life, not anymore, we need something better.

But how? it seems we can’t continue to use superheterodyne modules we have used for past 5 years.

It’s not just we want to change, customer needs it too, we continues to hear more and more customer suffers from interference at hot frequency such as 433MHz, interference like that will greatly reduce the remote distance, maybe down to several meters, compared to our test results of 150m+

So small improvements such as sensitivity improvement doesn’t fit our goal anymore, we need a huge step forward, we need a revolutionary component.

That’s why we start from begining, we chose SiLabs chip Si4432 / Si4463 as our new receiver module, these receivers use newer packet management technology, frequency tuning technology, software frequency control technology, so we can tune the frequency by software, not by hardware, that’s a step forward, also the module’s sensivity is far better, especially at FSK mode.

Hardware is foundation, also we have designed our software using frequency hopping technology, similar to those used on drones, to ensure stable link at all times, our engineer has spent months to fine tuning the results by theory and field test.

Finally, in our receiver testing equipped with this SiLabs module, our range is better than ever, also we use enhanced security technology called NeoCode to be better than ever.

For more information, please order samples of our new receiver to check out the details.

(To be continued…)

In coming post, I will share other stories in developing our latest receiver, on power supply circuit, please check back for more stuff!

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