Radio transmissions of relatively small amounts of data.

Radio wave is an electromagnetic wave; thus, radio frequency (RF) communication is where information is transmitted by modulating this electromagnetic wave. Radio waves have frequencies ranging from 3 kHz to 300 GHz, to be able to obtain the data we want we need to have a specific signal at which the receiver can pick up. 9Wifi, ZigBee, Z-wave are examples of wireless data transmission using radio frequency. We have looked at the three most promising ideas of radio frequency data transmissions, which are Wi-fi, Bluetooth and RF.Wi-fiWi-fi can transmit signals at many frequencies with the most common being 2.4GHz and 5GHz. Higher frequencies have a lower chance of interference as there are many devices which have frequencies at 2.4GHz which can crowd the channel. These signals can travel at distances up to 100 meters indoors, however this can vary due to the environmental conditions. Based on the IEEE 802.11 networking standards the most suitable wireless standard is the 802.11ac. This is a Wireless LAN data transmission system using radio waves to provide data transmission between devices. From all the other networking standards 802.11ac is much less prone to interference and has a greater speed of up to 6.933Gb/s and 720 Mb/s for 4 spatial streams. 10BluetoothBluetooth is a secure protocol, which is great for short-range and low-power wireless transmissions of relatively small amounts of data. Bluetooth protocol operates in the unlicensed 2.4GHz ISM band with the IEEE Standard being 802.15.1. 11 12 The data rate of BLE is 1Mb/s which good as we only need to transmit text values and not videos or music which would need a higher data rate. 13There is a next generation Bluetooth protocol called Bluetooth Low Energy (BLE) which uses a lot less power since it is not maintaining a constant connection. The BLE protocol only transmits data when needed, such that it will only start to constantly transmit data when the compression forces reach a certain value. Even then Bluetooth uses much less power than wifi, because it doesn’t not have to generate a stronger signal due to the signal not needing to travel as far. Bluetooth is also much simpler to use and integrate.Radio FrequencyWe can of course use radio frequency modules for data communication. As radio frequency has a very large range within the electromagnetic spectrum, frequency for radio for communication purposes is restricted by authorities in each country. However, 433MHz ISM (Industrial Scientific and Medical) band is license-free to use in many countries, with it being approved and regulated by the government. Therefore, Rolls Royce can implement this design in most of their generators worldwide.Compared to the other data transmission methods which uses radio frequency, we have discovered a RF transmitter chip which can operate normally up to 125 °C. The TDK5110F manufactured by Infineon, is a high power ASK/FSK (Amplitude Shift Keying/ Frequency Shift Keying) transmitter. 14 The TDK5110F transmitter has a high efficiency power amplifier of about 10 dBm at 3V, which prevents the system to not take too much power away from the generator. Similar to the BLE operation there is also Smart RF where the transmitter can go in sleep mode due to low current consumption for power saving.The connectivity chip can either be ASK or FSK, these are digital modulation techniques. A FSK transmitter is less susceptible to noise interference. This is due to ASK’s method of transmission which looks at peaks in frequency. There will be other frequencies affecting the amplitude of the signal, as there will be a lot of RFI within the electromagnetic generator. Comparing to the FSK technique which looks at the changes in frequency over a period of intervals. FSK uses larger bandwidth which reduces bandwidth efficiency however as we are only transmitting digital values we can ignore this.OverviewThe overall advantages are that all RF protocols have a suitable data rate, we only need to transmit numbers which thus we would not need a high data rate.  For this function the distance at which the signals can travel is not a very important factor as the transmitter and receiver circuits is less than a meter apart, which all these protocols are able to do. Radio frequency for data transmission is generally accurate and efficient, with the process being well known and widely researched.  Using radio frequency communication would be simple to integrate in the system with no complex circuitry. A great disadvantage for using the Wifi and Bluetooth protocol is obtaining a connectivity chip which would be able to operate in extreme conditions. The temperature of the air around the rotor can range from 100 to 200°C, however most industrial connectivity chips can only operate up to 85°C. We have found chips which can operate at 105°C and 125°C, for Bluetooth and general RF.Also within the electromagnetic generator there will unwanted electromagnetic frequencies which will cause interference to the modulated signal travelling from the transmitter to the receiver, causing the signal to be disturbed and distorted. This can cause the performance to degrade and loss of functionality. We cannot specify or know these frequencies, so it is best to assume any RF protocol would have interference to its signals. The data being transmitted can also be obstructed by physical materials. The generator is mostly made from metal, and metals which are electrically conductive materials can reflect and absorb radio waves which prevents the data travelling from the transmitter to the receiver. 15 Therefore, to prevent this obstruction we can locate the RF transmitter chip in direct view to the receiver module. The RF module would be integrated to the microcontroller which is located at the rotor. The receiver chip will be located at the stator giving the data the ability to travel when the transmitter and receiver modules are in direct line of sight when rotating where there will be no obstruction