An analysis of the autodyne effect of a radio-pulse oscillator with frequency modulation

Abstract

The results of investigations of an autodyne oscillator with concurrent pulse-and frequency modulation are presented, with the oscillator being affected by its own reflected radiation. The main relations for the analysis of the autodyne response with respect to the time delay of the reflected radiation are presented for the case of an arbitrary frequency modulation law. Special features of self-oscillations of such autodynes are addressed, which permit improvement of the characteristics and extension of the functional capabilities of autodyne systems in SRR applications. The analytical results are verified using the experimental prototypes of the autodyne sensors based on the oscillators employing the mm-range Gunn diodes operating on well-known principles.

Frequency Deviation of Injection-Locked Microwave Autodynes

“…From the formula (19) it can be seen that by varying the parameters k ex and  0 it is possible to choose the required values of the ILAD frequency deviation. The calculation by the formula for the values of Q ex = 150, k ex = 0.1, V r = 1000 m/s and cos 0 = 1 gives the gain from the use of ILAD Δω AD / Δω ILAD = 100.…”

“…One of the most important parameters of both radio frequency and laser AD as well as AD with various types of modulation is the so-called feedback parameter (FBP), C FB = Δω AD τ, where ω AD is the autodyne frequency deviation value; τ is the delay time of the reflected microwave radiation [15], [18][19][20]. The physical meaning of this parameter FBP is the phase modulation index of the autodyne response.…”

Dynamics of autodyne response formation in microwave generators

“…A more complex model that accounts for the mentioned phenomena, is considered in [17,18] when analyzing autodyne effect in radio-pulse generators, including those with additional frequency modulation. In these papers authors use the step method when solving autodyne equations to demonstrate that the process of formation of instantaneous autodyne response values that depend on the distortion parameter is accompanied by periodic amplitude and frequency leaps, which essentially increase the whole process duration.…”

“…This method was first applied to autodynes in [8,[17][18][19]. According to the method let's write down a sequence of main relations for a step-wise phase calculation d( ) n t of autodyne response, normalized relative autodyne amplitude a t n n ( ) and frequency c c n n n a…”