The problem of TM-wave scattering and radiation from a finite number o
f thick slits in a parallel plate waveguide is solved. The Fourier tra
nsform and the mode matching are used to obtain simultaneous equations
for the field inside the slits. The simultaneous equations are solved
to obtain a series solution which is amenable to numerical computatio
n. The numerical computations are performed to illustrate the behavior
s of scattering, transmission, and reflection in terms of incident ang
le, slit size and operating frequency. The presented solution is compu
tationally very efficient and useful for slotted-waveguide leaky-wave
antenna applications.