spiral ring structure

spiral ring structure

[′spī·rəl ′riŋ ‚strək·chər]
(astronomy)
A lunar crater in which ridges spiral inward from the main wall across the floor.
References in periodicals archive ?
In addition, the spiral ring structure extends the route of the surface currents and miniaturizes the size of the proposed Antenna.
In comparison to the conventional monopole structure, the proposed antenna has a more compact size of 28 mm x 20 mm x 1 mm due to the spiral ring structure extends the route of the surface currents.
The spiral ring structure provided a shunt capacitance between the outer and inner rings which increase the mode of the input reactance.
By inserting the spiral ring structure into the strip of the conventional monopole, the radiation pattern characteristics at higher operating frequencies are improved.