The concept of a time-modulated reflector array is introduced and investigated. A TMRA is proposed as a variant of a conventional time-modulated array. A TMRA is potentially simpler to implement in hardware as it does not require a complex feed structure. A simple 8 element TMRA is analysed using both array-factor theory and full-wave electromagnetic simulation software. The switching sequence applied to the TMRA is configured to produce radiation patterns with low sidelobe levels. The performance of a TMRA consisting of ideal, isotropic elements is compared to that of TMRA consisting of diode controlled dipole elements.