In this letter, a novel wideband traveling wave power divider/combiner based on the finline with irises is presented and studied. Experiments on the four-way passive divider/combiner demonstrate a minimum overall insertion loss of 1.5 dB at 35.8 GHz, and the insertion loss across 32-38 GHz is less than 2.5 dB.

In this paper, a novel eight-way Ka-band spatial power combining structure based on SIW/HMSIW is presented and studied. The power-combining structure is realized by transitions between HMSIW and parallel multiport planar microstrip lines. The power combiner is designed and fabricated in 33.5-35 GHz. The measured results show a good agreement with simulation and a combining efficiency of 72% is achieved at 34.3 GHz.

In this letter, a new definition of two-stage spatiotemporal approach, called ICA-WFS (Independent-Component-Analysis-Weighted-Frequent-Substructure) is proposed. To facilitate capturing abnormal behavior across multiple networks and dimensionality reduction at a single Point of Presence (PoP), ICA is applied. With application of WFS, an complete graph is examined, unusual substructures of which are reported. Experiments are conducted and, together with application of backbone network (Internet2) Netflow data, show some positive results.

In this letter, an improved triple-tunable frequency synthesizer structure to achieve both high frequency resolution and fast switching speed without degradation of spurious signals (spurs) level performance is proposed. According to this structure, a high performance millimeter-wave frequency synthesizer with low spurious, low phase noise, and fast switching speed, is developed. This synthesizer driven by the direct digital synthesizer (DDS) AD9956 can adjust the output of a DDS and frequency division ratios of two variable frequency dividers (VFDs) to move the spurious components outside the loop bandwidth of the phase-locked loop (PLL). Moreover, the ADF4252 based microwave PLL can further suppress the phase noise. Experimental results from the implemented synthesizer show that remarkable performance improvements have been achieved.

A new kind of 3D power divider based on a half-mode substrate integrated circular cavity (HSICC) is proposed. This novel power divider can reduce the size of a power divider based on normal substrate integrated circular cavity (SICC) by nearly a half. To verify the validity of the design method, a two-way X-band HSICC power divider using low temperature co-fired ceramic (LTCC) technology is designed, fabricated and measured.

In this paper, we propose a wideband four-way turnstile-junction waveguide divider/combiner in the Ka-band. The proposed divider/combiner has an insertion loss of less than 0.8 dB over the frequency range of 28–39.5 GHz. A power combiner amplifier using this circuit and four MMIC amplifiers has been demonstrated with 83% combining efficiency at 34.9 GHz. The measured results show that the turnstile-junction waveguide divider-combiner is a suitable element for developing a broadband millimeter-wave spatial power combiner amplifier.

In this letter, a novel 4-way X-band spatial power divider/combiner has been developed using a modified quasi-Yagi antenna transition. The divider has an insertion loss of less than 0.5 dB and a power balance of +/-0.8 dB over a bandwidth of 3.5 GHz in the X-band. A power combiner amplifier using this circuit and four MMIC amplifiers has been demonstrated with 84% combining efficiency. The obtained results show that the modified quasi-Yagi antenna is a suitable element to develop a broadband spatial power combiner.

In this letter, a broadband coupler is presented that makes use of a half mode substrate integrated waveguide (HMSIW) technique using a printed circuit board process. The coupler is realized by a parallel HMSIW line which couples energy by magnetic field. Compared with micro-strip coupler and conventional HMSIW coupler, it has lower loss and better Electromagnetic Compatibility owning to the closed field structure. Compared with SIW coupler, it has smaller size and lower cost owing to the half TE10 model. The coupler is simulated and measured at 8-12 GHz. Measured results show a good agreement with simulation.

In this paper, a novel slow-wave half mode substrate integrated waveguide (SW-HMSIW) structure is presented and experimentally demonstrated, and some interesting slow-wave propagation effects are obtained. The SW-HMSIW enables the cutoff frequency reduction and phase velocity to decrease without sacrificing its performance at the same lateral dimension, which equivalently reduces the lateral dimension and longitudinal size at the same frequency. Specifically, with the different loading microstrip width, a cutoff frequency reduction of 16%, 25%, 30% is achieved compared to the conventional HMSIW at the same lateral dimension. Both lateral and longitudinal size reductions significantly extend the operating range of SIW structures to low frequency region.

A novel resonant eight-way divider/combiner based on a double-layer finline is presented and studied. Experiments on the compact eight-way passive divider/combiner demonstrate a minimum overall insertion loss of 1 dB at 35.3 GHz, and the inserting loss across 34-36 GHz is less than 1.9 dB.

A novel resonant four-way divider/combiner based on finline is presented and studied. This divider/combiner designed in 34-36 GHz is composed of new probe coupling units between finline to microstrip lines. The measured power-combining efficiency of this circuit at 34.85 GHz is 83%.

A high-rate coding scheme that polar codes are concatenated with low density generator matrix (LDGM) codes is proposed in this paper. The scheme, referred to as polar-LDGM (PLG) codes, can boost the convergence speed of polar codes and eliminate the error floor behavior of LDGM codes significantly, while retaining the low encoding and decoding complexity. With a sensibly designed Gaussian approximation (GA), we can accurately predict the theoretical performance of PLG codes. The numerical results show that PLG codes have the potential to approach the capacity limit and avoid error floors effectively. Moreover, the encoding complexity is lower than the existing LDPC coded system. This motives the application of powerful PLG codes to satellite communications in which message transmission must be extremely reliable. Therefore, an adaptive relaying protocol (ARP) based on PLG codes for the relay satellite system is proposed. In ARP, the relay transmission is selectively switched to match the channel conditions, which are determined by an error detector. If no errors are detected, the relay satellite in cooperation with the source satellite only needs to forward a portion of the decoded message to the destination satellite. It is proved that the proposed scheme can remarkably improve the error probability performance. Simulation results illustrate the advantages of the proposed scheme