This paper presents a novel type of waveguide monopulse feeder, which has the concept of a space feed, suitable for liner phased array antenna. The design methods and measurement results of the 2-to-39 port feeder at X-band are described. Measurement results show that this feeder has characteristics of the required optimum 1-D nionopulse power distribution, low insertion loss and good input match. (c) 2007 Wiley Periodicals, Inc.