Rotman lens-fed aperture coupled array antenna at millimeter wave

Compact Rotman Lens Structure Configurations to Support Millimeter Wave Devices

“…(8), all contours in the conformal lens can be generated so that its true time delay properties are the same as the conventional lens. It should be noted that since the geodesics equation is applied on its local coordinates, i.e., cylindrical coordinate system for a cylindrical surface, in the second step to conform the lens, we apply (8) in the local geodesics coordinates of the surface. In this case, this local coordinate system has its origin at O local (0, 0, −R), and its unit vectors are x loc = x, y loc = − z , and z loc = y .…”

“…In the past few decades, methods to improve the magnitude and phase performance of Rotman lenses have been considered for the conventional lens equations [2][3][4][5][6][7][8] or using optimization methods [9][10][11]. These lenses can be used for many applications such as multi-beam wireless communication systems in military [12][13][14][15].…”

“…These lenses can be used for many applications such as multi-beam wireless communication systems in military [12][13][14][15]. With the development of fabrication technologies, numerous Rotman lens designs have been developed employing different techniques including microstrip [2,[5][6][7][8], graded dielectric substrates [16] or substrate integrated waveguides [17][18][19][20][21][22][23][24]. However, these designs still have a planar structure with a large electrical size which makes it difficult to integrate them into modern devices such as smart watches, mobile phones, curved TVs, or GPS devices, etc.…”

Compact multi‐layer microstrip Rotman lens design using coupling slots to support millimetre wave devices

“…Rotman lens, which was first introduced by Rotman and Turner in 1962 [1], is a multiple-input and multiple-output analogue beamformer that creates a specific phase taper at its output ports to feed a linear array antenna. Since then, numerous different methods were proposed to improve the magnitude and phase performance of Rotman lenses using the conventional lens equations [2][3][4][5][6][7][8][9] or based on optimisation methods [10][11][12]. Due to its simple structure and cost-effective fabrication process, Rotman lenses can be used for many applications such as multi-beam wireless communication systems for the military [13][14][15][16].…”

“…Due to its simple structure and cost-effective fabrication process, Rotman lenses can be used for many applications such as multi-beam wireless communication systems for the military [13][14][15][16]. With the development of materials and fabrication technologies, several Rotman lens designs have been developed employing different techniques including microstrip [2,[5][6][7][8], graded dielectric substrates [17] or substrate integrated waveguides [18][19][20][21][22][23][24][25]. However, these designs still have a planar structure with a large electrical size which makes it difficult to integrate them into compact modern devices.…”