Consider an antenna with electric field intensity in the \(x y\)-plane \(E(\varsigma)\). This electric field is generated by a current distribution \(D(y)\) in the \(y z\)-plane. The electric field intensity is computed using the integral

\[
E(\varsigma)=\int_{-r / 2}^{r / 2} D(y) \exp \left(2 \pi j \frac{y}{\lambda} \sin \varsigmaight) d y
\]

where \(\lambda\) is the wavelength and \(r\) is the aperture. (a) Write an expression for \(E(\varsigma)\) when \(D(y)=d_{0}\) (a constant). (b) Write an expression for the normalized power radiation pattern and plot it in \(\mathrm{dB}\).