Radio Frequency Integrated Circuits Prof Cameron Charles ECE CS 5720 6720 April 17 2007 Overview Introduction to RFICs Utah RFIC Lab Research Projects Low power radios for Wireless Sensing Ultra Wideband radios for Bio telemetry ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 2 What is an RFIC Internet An integrated circuit that uses inductors Services Analog integrated circuits that operate at PDA high Bluetooth radio frequencies typically for Headset MP3 Player communications Example cell phone Camera ECE CS 5720 6720 April 17 2007 GPS Cameron Charles Slide 3 Radio Concepts Examine the functional blocks in a radio Consider transmitter receiver is inverse ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 4 Why Upconvert Microphone output is in 0 3 kHz range Efficient Antennas have length 4 Spectrum is allocated to avoid interference ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 5 Mixer Operation Mixer moves the input signal to a higher frequency through multiplication cos 1 cos 2 cos 1 2 cos 1 2 ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 6 Mixer Mixer upconverts baseband voice signal to the oscillator frequency ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 7 Power Amplifier Amplifies the signal to higher levels so that it can drive the antenna ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 8 Filter Eliminates spurious emissions that could interfere with others ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 9 Antenna External to the RFIC Converts current voltage signal to radiated electro magnetic waves ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 10 Complete RFIC Implementation 12 5 mm2 in 0 18 m CMOS process ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 11 Overview Introduction to RFICs Utah RFIC Lab Research Projects Low power radios for Wireless Sensing Ultra Wideband radios for Bio telemetry ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 12 Utah RFIC Lab Founded way back in 2007 We research novel circuit architectures and techniques for RFIC functional blocks Research Methods 1 2 3 4 5 6 7 Analyze circuit problem come up with solution High level simulations in Matlab Circuit level simulations in Cadence Layout physical circuit in Cadence Send to foundry e g MOSIS for fabrication Test and characterize the returned IC Publish results in a prestigious journal ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 13 RFIC Lab Members 3 PhD students 1 MS student 2 undergrads and 1 visiting scholar Ondrej Novak PhD Wei Wu PhD UWB for bio telemetry UWB for bio telemetry Jeff Spiegel PhD Reconfigurable Frequency Synthesizers Manohar Nagaraju MS Process Variation in DLLs Roger White UG ECE CS 5720 6720 April 17 2007 Ahmed Ragab PhD Phase locked loops Low power radios for wireless sensing Tyler Squire UG Cameron Charles Phase locked loops Slide 14 Overview Introduction to RFICs Utah RFIC Lab Research Projects Low power radios for Wireless Sensing Ultra Wideband radios for Bio telemetry ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 15 Why sensor networks A wide range of applications Industrial monitoring Control manufacturing processes Building automation Regulate temperature light etc Asset Management Inventory control RFID Environmental Monitoring Facilitate biology research ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 16 Why wireless Mobility of sensing nodes Can be used for animal tracking Reduced size and cost High levels of integration lead to fewer components and reduced cost Less intrusive Eliminating the wired infrastructure lessens the impact on the environment being monitored Large scale deployment Low cost and small size facilitate dense ad hoc networks ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 17 Anatomy of a WSN Node ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 18 Commercial WSN Hardware Crossbow Mica2 Plug in sensor boards 90 mW power consumption Lifetime on the order of several days with continous operation less with sensor boards Built with off the shelf hardware 40 kbps data rate ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 19 Integrated WSN Hardware Higher levels of integration Reduced cost and size Reduced power consumption Operation Published Off the shelf 8b A D conv 0 031 nJ 13 5 nJ 8b P inst 0 012 nJ 0 20 nJ Tx Rx 8b 32 nJ 2500 nJ Radios with sub mW power consumption ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 20 Motivating Application Stream temperature monitoring in Red Butte Canyon Working with Dr Neal Patwari s group and faculty from the Biology Department Deployed test network this past summer Used Crossbow Motes with thermocouples to measure stream temperature every 10 min Data was transmitted to a gateway node that logged the measurements ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 21 Objectives for Future Work Develop power scavenging add ons to extend system lifetime Research low power radios to reduce overall power consumption Deploy a more extensive sensor network with additional sensing capabilities Wind levels Water uptake in trees ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 22 Overview Introduction to RFICs Utah RFIC Lab Research Projects Low power radios for Wireless Sensing Ultra Wideband radios for Bio telemetry ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 23 What is Ultra wide band The modern frequency spectrum is a pretty crowded place We want to transmit in desirable frequency bands without interfering with other users Transmit at low enough power levels to appear as noise to other users ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 24 What about data rates Problem Very low power levels mean very low data rates Observation Data rates depend on both power and bandwidth Solution Compensate for low power levels with very wide bandwidths The FCC defines an UWB signal as one having a bandwidth 500 MHz ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 25 How can we make UWB signals Standard modulation techniques are limited to narrow bandwidths due to channel variation Two alternatives Impulse based UWB OFDM based UWB ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 26 Relative Merits of UWB OFDM Higher complexity higher power Potential for higher data rates Well suited for consumer applications e g wireless USB Impluse based Simple architectures lower power Better suited for niche applications where power is a great concern ECE CS 5720 6720 April 17 2007 Cameron Charles Slide 27 Motivating