A Novel Construction Concept for Linear Delay Lines

Previous attempts to design lumped parameter delay lines having linear phase characteristics required the use of compensating capacitors or coils. This paper presents a novel concept in construction techniques which results in a linear phase delay line without the necessity of resorting to any compensating components. A step-by-step design procedure for a low-loss linear delay line is used to illustrate this new construction technique. This novel line has a nominal characteristic impedance of 500 ohms, delay of l0 microseconds, low attenuation, and a cutoff frequency of 4 megacycles. This new work is based upon the theoretical treatment of the ideal low-pass filter by Golay;¹the ideal parameter relationships have been reduced to practical design considerations involving unique geometric placements of ferrite cored components.