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Development of a Programmable Ultrasonic Receiver

Chris Allen (callen@eecs.ku.edu)

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OutlineUltrasonic signals

Ultrasonic receiver applications

Ultrasonic receiver requirements

Candidate component technologies

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Ultrasonic signalsInaudible to humans

Some animals and insects use ultrasonic signals for communication, navigation, hunting, etc.

Humans use ultrasonic signals for structures testing, medical applications (imaging, flow measurement), industrial processes, and ranging/communication

SpeciesApproximate Range (Hz)

elephant 16 - 12,000 goldfish 20 - 3,000 catfish 50 - 4,000 tuna 50 - 1,100

bullfrog 100 - 3,000 tree frog 50 - 4,000 canary 250 - 8,000

parakeet 200 - 8,500 cockatiel 250 - 8,000

owl 200 - 12,000 chicken 125 - 2,000 human 64 - 23,000

dog 67 - 45,000 cat 45 - 64,000 cow 23 - 35,000

horse 55 - 33,500 sheep 100 - 30,000 rabbit 360 - 42,000

rat 200 - 76,000 mouse 1,000 - 91,000 gerbil 100 - 60,000

guinea pig 54 - 50,000 hedgehog 250 - 45,000 raccoon 100 - 40,000ferret 16 - 44,000

opossum 500 - 64,000 chinchilla 90 - 22,800

bat 2,000 - 110,000 beluga whale 1,000 - 123,000

porpoise 75 - 150,000

MediumSpeed (m/s)

Air at 0° C 331Air at 20° C 343

Water at 20° C 1,482Lead 1,960Glass 5,640Steel 5,960

Compared to the speed of light, the speed of sound is very slow

(6 orders of magnitude lower)

1-cm EM wavelength 30 GHz in air 1-cm acoustic wavelength 33 kHz in air

Band Frequency Range Users

infrasound 0 to 20 Hzelephants, whales,

the earth

audio 20 Hz to 20 kHzhumans, insects,

animals, fish, sonarultrasound 20 kHz to 30 kHz rodentsultrasound 20 kHz to 75 kHz insectsultrasound 20 kHz to 160 kHz bats, dolphinsultrasound 100 kHz to 2 MHz structures testingultrasound 1 MHz to 10 MHz medical applications

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Ultrasonic receiver applicationsThe availability of an ultrasonic receiver enables several applications

• Ultrasonic radar system (when used with an ultrasonic transmitter)Applications include distance measurement, wind speed measurement, target detection / identification / tracking, ultrasonic imaging

• Ultrasonic spectrum analyzerApplications include signal characterization/classification, propagation channel characterization, radiation pattern measurement, ambient noise measurement

• Ultrasonic communicationsApplications include wireless signal distribution (non line-of-sight), covert communications, communication through structures (walls, floors, pipes)

• Ultrasonic testingNon-destructive testing, industrial sensors

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Ultrasonic receiver applicationsThe motivations for development of this programmable ultrasonic receiver include:

• Development of an ultrasonic radar systemEnables demonstration of various radar concepts for teaching/trainingProvides quick and low-cost evaluation of new radar concepts

• Development of an ultrasonic spectrum analyzerUseful for system characterization and troubleshooting

• Development of precision ultrasonic range measurement systemUseful for avionics (formation flying UAVs)

• Development of a wind speed measurement systemTo measure the vertical wind component near a wind turbine which may increase its conversion efficiency

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Ultrasonic receiver requirements Operating frequency range 30 kHz to 50 kHz

Signal bandwidth 1 kHz to 20 kHz

Dynamic range 50 dB

Number of channels 4

Output format USB interface

Final assembly custom printed circuit board

Size (max) 2.25” x 4” x 0.625” (10 cm x 5.5 cm x 1.5 cm)Weight (max) 80 gPower (max) 5 V @ 100 mA, 500 mW

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Candidate component technologiesTransducer

Knowles SPU04010HR5H MEMS microphone 20 kHz to 80 kHz

AmplifierLinear Tech LT1208 hi-speed op amp 45 MHz bandwidthLinear Tech LTC6910 prog. gain amplifiers 11 MHz bandwidth

MixerPhilips SA602A double-balanced mixer 500 MHz fmax

Local oscillatorLinear Tech LTC6903 programmable oscillator 1 kHz to 68 MHzinput for external LO

ProcessorArduino Uno 8-bit microcontroller 5 V, 16 MHzArduino Due 32-bit ARM microcontroller 3.3 V, 84 MHz

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Candidate receiver circuit diagram(only one channel shown)

Ultrasonic Tx board already developed

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