Design of traveling-wave equidistant slot antennas for millimeter-wave applications

Traveling-Wave Series-Fed Patch Array Antenna Using Novel Reflection-Canceling Elements for Flexible Beam

“…In the 24GHz ISM band, the efficiency problem will be more critical. Thus, a radiating matching load (RML) is employed as the last element in a TSPAA to increase the radiation efficiency [24]- [26].…”

“…Consequently, the in-phase excitations and large coupling power are allowed for the TSPAAs. The reflectioncanceling element is first proposed for designing waveguide slot array antenna [20]- [24]. By introducing a matching slot pair [20], an inductive vertical post [21], and an associated wall [22] near the waveguide slot antenna, the reflection from the slot element can be canceled due to the alternating-phase reflection from these introduced structures.…”

“…Then, the method is extended to design the SIW slot antenna array [23], where the inductive post in [21] was replaced by the plated via. With the similar reflection-canceling element, an 8-element SIW slot array with broadside radiation pattern is designed with -22.5dB sidelobe level (SLL) [24].…”

Transverse slot with control of amplitude and phase for travelling‐wave SIW antenna arrays

“…Substrate integrated waveguide (SIW) slot antenna arrays allow a large variety of slot configurations and feeding techniques and have been extensively studied in recent years [1–8]. Arrays are classified into two different types: standing‐wave and travelling‐wave arrays.…”

“…Several methods for suppressing these reflections have been published. The most common technique uses an inductive post inserted into a waveguide near to a longitudinal slot antenna element [5], a transverse slot antenna element [6], or a polarised slot antenna element [7]. In [6], one reflection‐cancelling post is placed into a hollow waveguide near a transverse slot.…”