This paper proposes a reflection-type wideband 360 ° analogue phase shifter. The phase shifter employs a branchline coupler circuit to achieve a wideband operation and a varactor-diode circuit to achieve a wide phase-shift range. Analytical formulas are derived to optimize the parameters in the coupler circuit for wideband operation and reduced attenuation ripple, and in the varactor circuit to...

For many applications, wideband signals are exploited for localization. A wideband signal is any signal whose energy is distributed over a bandwidth that is large in comparison to the signal’s center frequency. For example, ultrawideband (UWB) noise radars use wideband offering low probability of detection (LPD), while achieving good target detection and high resolution [1]. In the acoustic veh...

The demand of communicating at higher data rates can be easily met by using wideband signals [1], rendering the problem of estimating the direction of arrival (DOA) of wideband sources quite important. Multipaths, scatterers etc. present near the transmitter provide spatial bandwidth to these sources, which seriously degrade the performance of traditional DOA estimation techniques, designed ass...

A concept for wideband electronic steered array using analogue FIR-filters has been formulated. This paper focuses on microwave applications, e.g. wideband antenna radiation pattern, where we explain the design of a desired radiation pattern for bandwidth 2:1. Therefore we consider a linear narrowband radiation pattern and expand it to a wideband array synthesis. The requirements for higher ban...

Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, ...

Wideband spectrum sensing is an essential functionality for cognitive radio networks. It enables cognitive radios to detect spectral holes over a wideband channel and to opportunistically use under-utilized frequency bands without causing harmful interference to primary networks. However, most of the work on wideband spectrum sensing presented in the literature employ the Nyquist sampling which...

The migration of telecommunication towards wideband transmission may also introduce new types of degradations. This paper focuses on the influence of echoes. The different frequency content of un-cancelled residual echoes in wideband transmission, especially the signal energy in higher frequency ranges above 3 kHz, significantly changes the echo perception and echo disturbance compared to the n...

The calculation of wideband digital beamforming using traditonal methods is so large that it is hard to realize in project. This paper describes a wideband digital beamforming method on the base of stretch processing for linear frequency modulated (LFM) waveforms. This method offers advantages that are moderate data rate for wideband signal processing by reducing the signal bandwidth greatly. I...

Talker echoes are one of the influencing factors which need to be addressed during migration of telecommunication towards wideband transmission. A recently carried out talking and listening test (TALT) focusing on wideband echo disturbances is introduced and the results are summarized. The E-Model, a planning tool for telecommunication networks, considers the degradation of the speech quality c...

This Paper presents the design of a wideband variable gain amplifier (VGA) using 0.18 μm standard CMOS technology. The proposed VGA realizes wideband flat gain using wideband flat negative capacitance. It achieves a 3 dB gain bandwidth of 1 GHz with a maximum gain of 23 dB. Also, it shows P1 dB of −33 to −6 dBm over the gain range of −28 to 23 dB. The overall current consumption is 5.5 mA under...