Cascoda is a fabless semiconductor company based in Southampton, UK. The company was founded by Bruno Johnson (CEO) and Wolfgang Bruchner (CTO) in 2007. We’ve invited Bruno to offer you an introduction to the company, its 6LoWPAN technology and the relationship between Cascoda and Imagination.
Long before founding Cascoda, we had been working with communications technology for our entire careers. As such we had pondered whether it would be possible to overcome the limit of range for wireless personal area network (WPAN) standards by improving receive sensitivity, without compromising receive power consumption.
The solution to this problem has eluded radio system engineers for decades. In 2009 we started Cascoda and set out to solve this problem.
A little context
There are multiple wireless standards in use today, including Wi-Fi, Bluetooth or ZigBee.
Wi-Fi® is allowed to transmit with up to 100mW power, while wireless personal area network (WPAN) standards such as Bluetooth and ZigBee are only allowed to transmit up to 10mW power in most of the world. As such, WPAN devices have very limited range as compared to Wi-Fi. This limit of range becomes a problem when WPAN devices are required to operate across larger areas such as across a whole house, office building or industrial site.
So what do existing WPAN systems look like today?
Semiconductor radios for the WPAN are required to both transmit and receive radio signals. Such devices are known as radio transceivers. The quality of a radio transceiver is dependent on transmitter efficiency and receiver sensitivity. The receiver sensitivity was the focus for Cascoda’s research.
A more sensitive receiver is one which is able to recover data reliably from a weaker transmitted signal. Sensitivity is limited by two significant factors. The first of these is the noise generated in the receiver front-end circuits. The other is the amount of noise that can be tolerated when recovering data from the received signal in a circuit known as a demodulator. By reducing the generated noise in the receiver and/or improving the noise tolerance of the demodulator, a transceiver will operate over a longer range, due to increased receive sensitivity.
Existing receiver topologies use one of two demodulation schemes, coherent or non-coherent. Coherent schemes deliver excellent noise tolerance, at the expense of high power consumption. Non-coherent schemes, however, trade poor noise tolerance in return for low power consumption. Both coherent and non-coherent schemes therefore demonstrate certain significant disadvantages due to fundamental limits of the demodulation scheme.
How Cascoda solved this problem
Cascoda overcame this problem with a particularly elegant solution, which has received patent grants on three continents. Cascoda has developed a completely new type of receiver architecture that does not suffer from this enforced trade-off, offering near-ideal noise tolerance and much lower power consumption than a coherent scheme. The power saved by Cascods’s demodulator architecture allows Cascoda to put more power into the receiver front-end, thus lowering the noise floor. Overall, this delivers a device with greater sensitivity and thus increased range.
The benefits of the Cascoda chip
The benefit of Cascoda’s technology is a significant increase in range without compromising on power consumption. In the domestic setting, this increase in range may allow for whole-house coverage, without the need for external power amplification. The corresponding saving in terms of lower system cost and reduced power consumption will allow for more battery and energy-harvesting powered applications, such as in water meters, gas meters and temperature monitoring.
The benefits of Cascoda’s technology can be summarized as follows:
- Equipment cost: Since Cascoda’s radios deliver a significant increase in range, through increased receive sensitivity, there is a less need for external power amplifiers, thereby reducing the cost of wireless modules.
- Installation cost: Longer range translates to greater data-link reliability, fewer repeater nodes, and therefore lower installation cost. This also lessens the need for skilled installers, and in many cases the consumer will be able to self-install.
- Maintenance cost: Where batteries are necessary, lower power consumption means that batteries will last longer, thereby minimizing maintenance cost.
Why the Creator Ci40?
Cascoda recognizes the challenges associated with delivering solutions for the IoT. We firmly believe that no one firm has either the resources or the expertise required to service this market. Hence Cascoda is set up to operate in a world of cooperation and collaboration.
As such Cascoda is very pleased to be collaborating with Imagination Technologies on the Creator Ci40 platform. The Ci40 is the most complete IoT kit we have seen. Moreover, the ecosystem that Imagination Technologies has built is impressive.
We’re very excited to announce that Creator Ci40 will be using the CA-821X chipset from Cascoda for IEEE 802.15.4 communications in the 2.4GHz band.
So, while Cascoda’s technology helps overcome the problem of range for low power IoT systems, we firmly believe that Ci40 and the ecosystem around it will help overcome the challenges associated with developing world-class IoT platforms for prototyping and volume production alike.