Integral equation from MATTHAEI book

This equation is from " Microwave Filters, Impedance Matching And Coupling Structures" by MATTHAEI, page 4.
Can anyone solve this equation?

this equation is actually came from chap 6, Network Analysis and feedback amplifier design by Bode, you can find out this book in EETOP

thanks

Can you suggest any book for microwave oscillator design.