E_{P} = [E_{0} \frac{1}{R r} \exp (i k R) d Σ] \times \sum_{m} K (θ) \exp (i k r_{m})

${E_P = \bigg[E_0 \frac{1}{Rr} \exp (ikR) \mathrm{d} \Sigma \bigg] \times \sum_m K (\theta) \exp (ikr_m)}$

Error