Range resolution versus angular resolution in a long slotted waveguide antenna

It is noted that there is a limit to the length of the slotted waveguide antenna (i.e. angular resolution) with respect to the minimum pulse width of the transmitted pulse (i.e. range resolution). It is not possible to get both high range and angular resolution in a radar using the slotted waveguide antenna. An expression is derived which shows that the product of range and angular resolution is constant. Therefore, if the angular resolution is increased, then range resolution will be decreased. For example, a slotted waveguide antenna of 6-m length gave a beamwidth of 0.4 degrees . The transmitted pulsewidth could not be lowered below 3T/sub t/=84 ns at 9375 MHz, where T/sub t/ is the transit time.<>