Design of Dissipative Band-Pass Filters Producing Desired Exact Amplitude-Frequency Characteristics

The purpose of this paper is to present a basic method of obtaining the exact required values for all circuit constants in a band-pass network using n finite-Q resonant circuits to obtain either of two types of exact amplitude responses; the socalled critical shape-coupled, Butterworth, or transitional type of response, and the so-called over-coupled or Chebishev type of response. The equation giving the gain obtained with the desired response shape is derived. Equations for the exact phase characteristics associated with the above exact amplitude characteristics are also given. Some comments are made concerning a somewhat similar method of design, which makes use of the so-called "poles" of the network. Design sheets are presented giving the necessary equations for single-, double-, triple-, and stagger-tuned networks to produce either of the above two amplitude-response shapes.