Overview

In the next four chapters, the oscillator fundamentals discussed previously are applied to the design of a number of specific oscillators. The schematics, analysis of the Bode responses, circuit peculiarities, and performance of these oscillators will be studied.

Oscillators using L-C, transmission line, SAW, and piezoelectric resonators are investigated in detail. Each of these resonator media has advantages and disadvantages, with suitability for different oscillator applications. The range of examples is not intended to be inclusive, but representative of techniques which may be applied to satisfy specific oscillator requirements.

Each oscillator type is studied by a unified analysis approach, the open-loop cascade gain-phase plot (with two exceptions). The vagaries of different oscillator types have yielded to practical solutions developed over the years by countless contributors. A unified analysis of these practical designs will provide insight into oscillator behavior and prepare the reader for development of oscillators for new and unique applications.

Sixteen oscillator types, listed in Figure 7-1, are studied. Oscillator configurations that utilize capacitive tapping of a simple tank resonator are Colpitts oscillators. Oscillator configurations that utilize inductive tapping of the resonator are Hartley. Clapp added a capacitor to the Colpitts [1]. The process of naming each variation or improvement to a classic design, as significant as they may be, soon gets out of hand. Giving correct credit is further complicated by the conversion of the classic vacuum tube designs to solid-state devices which bear little resemblance to the original active device. Oscillator types, other than those clearly...