Question

Spatial nulling subsystem replaces three element sectors of conventional base station with ____ disposed antenna elements.

(a) four spherically

(b) eight spherically

(c) four circularly

(d) eight circularly

I got this question by my school principal while I was bunking the class.

My query is from Smart Antenna in section Smart Antenna & Software Component Characteristics of Cognitive Radio

Answer 1

The correct answer is (d) eight circularly

To explain I would say: Spatial nulling subsystem replaces three element sectors of conventional base station with eight circularly disposed antenna elements. The signal is then preamplified and converted to digital form using eight wideband ADCs.