In this work, an electronically reconfigurable onedimensional guided wave fed slot array antenna is proposed. The individual antenna element making up the array is designed at X-band and is capable of switching between radiating and non-radiating states by use of a PIN diode used to control the operating frequency of the element. In addition to this discrete control of the phase constant (β), the average ON and OFF time of the individual elements is also used to taper the attenuation constant (α), and therefore the amplitude distribution, of the array which allows the reduction of the side lobe level (SLL) by virtue of time modulation. A 21 element linear array is fabricated and measured to validate the proposed concept in terms of beam scanning in the H-plane and SLL reduction. The limitations of the structure are also evaluated.