This paper proposes a compact dual‐band printed quadrifilar helix antenna (QHA) operating at GPS‐L1 (1575 ± 2 MHz) and L2 (1228 ± 2 MHz) bands. To generate the dual operating bands, two interconnected lines with unequal lengths are introduced as a radiating element. The closely allocated radiators resonate in quarter‐wavelength mode, which significantly miniaturizes antenna's size. Four shunt capacitors are loaded near ports to manipulate the mutual coupling between each two radiators, so that satisfactory matching condition with minimum active reflection at two target bands can be obtained simultaneously. Then, a compact feeding network consisting of on‐chip hybrid couplers is designed and connected to the QHA. Measured results show that the compact proposed antenna achieves peak gains of 1.5 dBic and 2.6 dBic at 1575 MHz and 1228 MHz, respectively. The axial ratios (ARs) at L1 and L2 bands are both below 2.5 dB, and the half‐power‐beamwidths (HPBWs) are as wide as 130° and 116°, respectively. As compared with reported works, the proposed antenna can achieve much more compact size (0.11 × 0.21 λ₀²) and dual‐band radiation at the same time.

中文翻译：

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紧凑的双频段印刷四线螺旋天线，用于实际手持设备

本文提出了一种紧凑的双频印刷四线螺旋天线（QHA），其工作在GPS-L1（1575±2 MHz）和L2（1228±2 MHz）频段。为了产生双工作频带，引入了两个长度不等的互连线作为辐射元件。紧密分配的辐射器在四分之一波长模式下产生谐振，从而极大地减小了天线的尺寸。在端口附近装有四个并联电容器，以控制每两个辐射器之间的相互耦合，从而可以同时获得令人满意的匹配条件，同时在两个目标频带上产生最小的有源反射。然后，设计了一个由片上混合耦合器组成的紧凑型馈电网络，并将其连接到QHA。测量结果表明，该紧凑型天线在1575 MHz和1228 MHz时可实现1.5 dBic和2.6 dBic的峰值增益，分别。L1和L2频段的轴比（ARs）均低于2.5 dB，半功率波束宽度（HPBW）分别高达130°和116°。与报道的作品相比，拟议的天线可以实现更紧凑的尺寸（0.11×0.21λ ₀ ²在同一时间）和双频辐射。