Scalar Highly Directive Circularly Polarized Full- and Half-Structured Holographic Metasurface-Based Ku-Band Leaky-Wave Antenna
Swarnadipto Ghosh, H. Priyadarshan, Chinmoy Saha
Abstract
Scalar meta unit-cell loaded, progressive phase modulated, circularly polarized (CP), holographic metasurface-based leaky-wave antenna (HMSLWA) is reported in this letter. A comprehensi<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</i>e numerical and analytical description of rectangular to polar transformed, progressive phase modulated surface impedance (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">surf</sub>) expression is discussed with necessary simulated and measured data validation of proposed half- and full-structured HMSLWA. Proposed full- and half-structured HMSLWA, having an overall dimension of 12.5<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{\bm{\lambda }}}_0} \times $</tex-math></inline-formula> 12.5<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{\bm{\lambda }}}_0}$</tex-math></inline-formula> and 12.5<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{\bm{\lambda }}}_0} \times $</tex-math></inline-formula> 6.5<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{\bm{\lambda }}}_0}$</tex-math></inline-formula> yields highly directive central beam (i.e., <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\bm{\theta }}$</tex-math></inline-formula> = <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\phi $</tex-math></inline-formula> = 0<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ $</tex-math></inline-formula>) with a maximum realized gain of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> = 25.11 and 21.17 dBic with 3.9<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ $</tex-math></inline-formula> and 4.3<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ $</tex-math></inline-formula> HPBW at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{{\bm{f}}}_{\bm{r}}}$</tex-math></inline-formula> = 15.51 GHz. A wide axial ratio bandwidth (ARBW) is achieved with an overall AR of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \leq $</tex-math></inline-formula>0.9 dB.