A novel architecture of the center-fed pinching antenna system (C-PASS) is proposed. In contrast to the conventional end-fed PASS, signals are fed from the center input ports and propagate towards both sides of the waveguide. By doing so, spatial-multiplexing gain can be achieved in a single waveguide. Based on the proposed C-PASS, closed-form expressions for the degree of freedom (DoF) and power scaling laws are derived. These theoretical results reveal that C-PASS can achieve \emph{twice} the DoF and an additional multiplexing gain of $\mathcal{O}(P_T \ln^4 N/N^2)$ compared to the conventional PASS, where $P_T$ and $N$ represent the transmit power and pinching antenna number, respectively. Numerical results are provided to demonstrate that substantial capacity improvements can be achieved through the enhanced DoF and multiplexing gain of the C-PASS.

翻译：提出了一种新颖的中心馈电夹捏天线系统（C-PASS）架构。与传统端馈PASS不同，信号从中心输入端口馈入，并向波导两侧传播。通过这种方式，可在单条波导中实现空间复用增益。基于所提出的C-PASS，推导了自由度（DoF）和功率缩放定律的闭式表达式。这些理论结果表明，与传统PASS相比，C-PASS可实现两倍的DoF以及额外的复用增益$\mathcal{O}(P_T \ln^4 N/N^2)$，其中$P_T$和$N$分别代表发射功率和夹捏天线数量。数值结果验证了通过C-PASS增强的DoF和复用增益能够实现显著的系统容量提升。