This paper describes the structure and operation of a new differential phase angular rate sensor and analyses it's response to input rotation. It employs a vibrating beam mass structure that is forced into an elliptical path when subject to rotation due to the Coriolis effect. Two sensing elements are strategically located to sense a combination of drive and Coriolis force on each to create a phase differential representative of the input rotation rate. A general model is developed describing the device operation. The main advantages of the phase detection scheme are shown, including removing the need to maintain constant drive amplitude, independence of sensing element gain factor and novel response shapes. A ratio of device parameters is defined and shown to determine the device response shape. This ratio can be varied to give a high sensitivity around zero input rate or a response shape not seen before, that can give maximum sensitivity around an offset from the zero-rate input. This may be exploited in an array configuration for a highly accurate device over a wide input range. A worked example shows how the developed equations can be used as design tools to achieve a desired response.