radar question important

A policeman uses a radar operating at a frequency f = 24 GHz to detect the speed of incoming cars. The detection angle is set at 30 degrees. Find the frequency band of the low frequency bandpass filter to cover speed range from 50 km/hr to 200 km/hr.

How do i solve this?
how do i use the angle of detection here?

thanks

http://cnx.org/content/m12578/latest/

This comment is a little out in left field, but maybe not. I may be reading too much between the lines.

Take a look at: www.radarbusters.com and see if "Radar Roy" has anything to help your situation.

His stuff is more salesmanship than technical.

i think use monopulse can do it

Can i solve by using the velocity component (ie using cosine of the angle)

i think y can use the microstrip antenna as the sensor, and then y use monopulse system to solve the incoming angle problem,use the doppler frequency to detect radix velocity and then use the monopulse angle to solve the speed, the microstrip antenna's main aim is to solve the volume problem!

may be the "radar handbook " is useful to your project!