RFbeam Microwave GmbH

RSP1 Radar Processor

Datasheet

14 Sample Schematics

For complete schematics, please refer to the RSP1_Eval-Kit user manual.

14.1 Amplifiers

14.1.1 Sensor Outputs

A moving object in range of a Radar sensor (often called “transceiver “) generates a low frequency output

signal. Frequency depends on the object speed. Amplitude depends on distance, reflectivity and size of

f

44Hz

km/ h

⋅

cosα

or

f

158Hz

m/ s

⋅

cosα

with

Note that the angle of the moving object reduces Doppler frequency.

Radar sensor signals have low frequency outputs called 'IF' outputs.

Most sensors of the K-LCx family do not have an integrated amplifier. This makes these devices

universal and low cost. Different applications need different amplification and frequency response.

Sensor output amplitude can range from less than 100nV to some mV .

14.1.2 Amplifier Structures

The following example schematics show 2 channel (I/Q) solutions with one- and two stage amplifiers.

Dual channel configurations need I/Q (sometimes called "stereo" sensors) like K-LC2, K-LC5, K-LC6 etc.

Dual channel configurations are state-of-the-art solutions with much better noise and interference

suppression than single channel solutions. Furthermore, dual channel allows distinguishing approaching

and receding objects.

Please refer also to Table 4: Useful signal level conversions.

Single channel solutions need less components and can be used with low cost sensors like K-LC1 or

K-LC3.

If only 1 channel is required, only amp of channel 'I' is is needed, but RSP1 inputs 'RADAR_I1'

and 'RADAR_Q1' must be connected together.

RSP1 provides an internal programmable gain amplifier with gains from 1 to 32 (0dB to 30dB).

Gain is set by parameter 'S09'. Default setting is 32.

A

- > in our examples

A

Maximum detection range is a function of the signal/noise (S/N) ratio at the RSP1 input.

Higher gain does not automatically mean higher detection range.

For more details on optimal amplification refer to the RSP1_Eval-Kit manual.

Dual amp stage structures allow higher external gains, higher bandwidth and lower gain.

If high speed detection at maximum range is required, dual amp stage is the right choice.

© RFbeam Microwave GmbH www.rfbeam.ch

December 11, 2015

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α

Radar sensor

moving

object