  In this paper we report the development of the design verification model
(DVM) of Rb atomic frequency standard. The Rb atomic frequency standard or
clock has two distinct parts. One is the Physics Package where the hyperfine
transitions produce the clock signal in the integrated filter cell
configuration and the other is the electronic circuits which generate the
resonant microwave hyperfine frequency, phase modulator and phase sensitive
detector. In this paper the details of the Rb Physics package and the
electronic circuits are given. The effect of putting the photo detector inside
the microwave cavity is studied and reported with its effect on the resonance
signal profile. The Rb clock frequency stability measurements have also been
discussed.
