Josephson voltage standards utilize microwave‐induced constant voltage steps in the dc characteristic of Josephson tunnel junctions. This paper describes the design and operation of array circuits with 108 and 2000 junctions connected in series. In contrast with similar realizations, simpleQ‐band equipment is used for the microwave supply. The microwave attenuation of 1000 junctions was about 1 dB. The version with 2000 junctions generated Josephson voltages up to 1.2 V when operated at 35 GHz. The stability times of the quantized levels were, under normal laboratory conditions (unshielded room), better than 10 min.