4
Force Mode Distributed Wave Oscillator
In this chapter, an electronic oscillator circuit that can provide accurate mul-
tiple phases of an oscillation and a phased-array power amplification system
areintroduced.The chapter presentsthe first measurementresultsof the ideas
presented in [1]. An oscillation can be formed across two independent con-
ductor loops by introducing an additional force mechanism across each of the
individual lines, forming a differential transmission medium for the oscilla-
tion wave. Two different approaches are proposed in Section 4.1 regarding the
application of this additional force mode that prevent the two complemen-
tary conductors latching up. In the delay-based first method, the signals at
certain points along each line are amplified through inverting amplifiers and
applied to the corresponding opposite phase points along the same line. The
force application point is calculated depending on the connecting line delays.
In the symmetry-based second method, the differential structure is shaped
symmetrically to create a meeting point for the opposite phase points of each
conductor in the center, thus eliminating the inaccuracy of the connecting line
delays. Section 4.2 goes over single-ended version of the oscillator as a radi-
ating element, which is called force-mode distributed wave antenna. Also
in Section 4.2, a unidirectional single-conductor version of force-mode dis-
tributed wave oscillator (FMDWO) is combined with a secondary pickup coil
to form a distributed oscillator amplifier. The proposed oscillator-transformer
scheme converts the unidirectional oscillator current in the primary coil into a
large-voltage swing in the second coil driving the antenna. By modulating the
oscillation frequency with baseband data using varactors or other capacitive
tuning elements, a topology that serves as a radio frequency (RF) transmitter
is obtained. By segmentation of the total loop into 2N sections, distributed
multiple local transformer loops are used to utilize the same circulating os-
cillator current with 360/2N phase difference. The system consisting of mul-
tiple sections each driving a separate antenna thus serves as a beam-forming
transmitter. Employing several of these systems with the desired phase differ-
ence through a phase-locked loop (PLL) enables a very high resolution pro-
grammable beam-forming transmitter. Section 4.3 summarizes the chapter.
4.1 Force Mode Distributed Wave Oscillation Mechanisms
The force mode distributed wave oscillator (FMDWO) technique described
in this work proposes an alternative approach for a wave oscillator that can
57
58 High Frequency Communication and Sensing: Traveling-Wave Techniques
V
tune
V
tune
V
tune
V
tune
A
B
V
DD
A
B
ph_180
ph_0
ph_90
ph_270
ph_180
ph_0
ph_270
ph_90
t
amp
t
con
t
d
FIGURE 4.1
Delay-based FMDWO circuit diagram.
provide unique advantages, such as even phase symmetry, compared to ex-
isting methods. The technique involves additional force mechanisms that
create oscillation in two independent differential conductors. The schematic
diagram for the delay-based first force mechanism is shown in Figure 4.1.
The circuit is built around the two independent transmission line loops. The
cross-coupled distributed inverting amplifiers shown in the figure boost the
differential traveling wave and compensate for the losses along the line, help-
ing to sustain the oscillation. The other set of inverting amplifiers boost the

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