Theory Of Optically Controlled Millimeter-wave Phase Shifters

Nonuniform layer model of an image‐guide millimeter‐wave phase shifter

“…From the knowledge of the plasma distribution N v ( y) the y-dependent complex relative permittivity r ( y) of the semiconductor with plasma present can be calculated according to the Drude-Lorentz formula (for example, see [6]), taking into account all types of carriers, photoinduced electrons (i ϭ e), light holes (i ϭ h L ), heavy holes (i ϭ h H ), and thermally ionisized holes (i ϭ h) with their respective density N i , collision frequency i , and effective mass m * i , where the photoinduced plasma density is given by…”

“…where ␥ slab ϭ jk 0 re slab (6) denotes the longitudinal propagation constant of the horizontal slab guide and k 0 ϭ /c 0 is the free-space wave number. The complex scalar potential function ( y) satisfies…”

“…Semiconductor waveguides with optically induced plasma layers have received considerable attention for their wide applications in controlling millimeter-wave devices. Switching, gating, phase shifting, filtering, coupling, and modulation by means of optical control have been demonstrated by several authors, mostly for applications in the W-band [1][2][3][4][5][6]. Therefore, a variety of waveguide structures have been discussed and analyzed, which mainly focus on the basic dielectric waveguide with a single uniform plasma-density layer on top [6], a buried uniform plasmadensity layer [7], and a uniform plasma-density layer on both the top and bottom of the waveguide [8].…”

“…Switching, gating, phase shifting, filtering, coupling, and modulation by means of optical control have been demonstrated by several authors, mostly for applications in the W-band [1][2][3][4][5][6]. Therefore, a variety of waveguide structures have been discussed and analyzed, which mainly focus on the basic dielectric waveguide with a single uniform plasma-density layer on top [6], a buried uniform plasmadensity layer [7], and a uniform plasma-density layer on both the top and bottom of the waveguide [8]. In addition, among the derivatives of the dielectric waveguide, optical control of the rib guides and image guides (both with a single uniform plasmadensity layer on top) have been studied [9].…”

Wideband Digital Phase Shifter with Low Insertion Loss

“…There are two kinds of phase shifter, one is the digital phase shifter, its phase shift in the way of change in accordance with a certain step to jump-type changes. The other is the analog phase shifter, its input control signal is an analog signal, so its phase shift is a continuous process of change [1].…”