─ A novel ultra-wideband (UWB) out-ofphase four-way power divider is presented. To achieve a division over a large frequency range, Tjunctions formed by slotlines and microstrip lines are utilized. Based on the transmission-line equivalent-circuit method, we derive the design equations of the proposed power divider. Furthermore, all measured results are in good agreement with the predicted desi...

A novel compact UWB antenna with 3.5/5.5 GHz dual notch-band characteristics is presented. The proposed antenna has a simple structure and compact size of 30 × 35mm2. Firstly, a compact modified rotated monopole antenna that covers UWB band is achieved. Then by inserting a λ/4 stub and etching two symmetrical λ/4 L-shape slots on the UWB antenna achieved before, a dual band-notched ultra-wideba...

In this paper, we propose a direct sequence ultra wideband (DS-UWB) radar system using a short-length pseudo noise (PN) sequence. The proposed DS-UWB radar reduces the correlation processing time by averaging out the noise in the correlator outputs, and thus, employs a short-length PN sequence unlike the conventional DS-UWB radar systems using multiple variable-length PN sequences. Numerical re...

In this paper, the effects of Bragg scattering on ultrawideband (UWB) signal transmission from periodic surfaces are reported. First, the frequency dispersive property of Bragg scattering is theoretically and experimentally confirmed. Next, the transfer function of both specular path and Bragg scattering are extracted. Then direct sequence UWB (DS-UWB) transmission simulations are conducted by ...

In this paper we propose frequency and time hopping pulse position modulation (FTH-PPM) ultra wideband (UWB) for multiple access communications. We have derived and investigated the bit error probability for the multi-user synchronous transmitter case in multipath channels with Additive White Gaussian Noise (AWGN). Simulation results show that bit error probability performance of FTH-PPM UWB ou...

Ultra-wideband (UWB) signals originated from research and development work on high resolution radiofrequency (RF) radar systems in the 1950-60s. The current FCC regulations in the US, define a UWB signal as having an absolute bandwidth which exceeds 500 MHz or fractional bandwidth over 20%. The FCC frequency band assigned to UWB systems extends from 3.1 GHz to 10.6 GHz, i.e. a bandwidth of 7.5 ...

This paper shows the design of a broadband low noise amplifier (LNA) for ultra-wideband (UWB) system on 0.18um CMOS process. The proposed LNA uses resistive shunt feedback technique and an inter-stage inductor as an inductive peaking to realize the flat gain throughout the UWB band. The designed UWB LNA has a noise figure lower than 3.5dB, gain above 20dB in the frequency range 3. 1-10.2GHz. It...

A novel transceiver design for ultra wideband (UWB) communication systems using the channel phase precoding (CPP) technique is proposed in this work. With the CPP-UWB transceiver, we encode data symbols using the reversed order of the channel phase. A simple phase estimation algorithm is presented for the CPP-UWB implementation. Owing to its ability to coherently combine the channel magnitude o...

A uniformly spaced comb taper slot antenna array is proposed for directional ultra-wideband (UWB) applications. The UWB array consists of four identical comb taper slot antennas, a mutistage with four-way microstrip UWB power divider, and four identical coaxial cable lines. A maximum gain of 15.5dBi within the band is obtained when the element separation is properly selected. The uniform spacin...

Antennas that are capable to radiate in the Ultra-wideband (UWB) range is a major area of current research. The UWB range is accompanied through the integration of Multiple-InputMultiple-Output (MIMO). In this paper, two circular monopole antennas are acting as the radiating elements. A T-shape stub is placed between the radiator elements to enhance isolation. The proposed antenna is capable of...