This master thesis has focused on the aspect of UWB antenna design for the impulse based UWB radar which is built on CMOS technology. The design of new UWB antenna faces some challenges. The antenna should be compact, preferably conformal, low cost for manufacture, and have good electrical performance, such as good matching, directional radiation performance over a wide band, good time response...

In this paper the impact of ultra wideband (UWB) interference on IEEE802.11b WLAN performance is studied through experimental tests. Extremely high power UWB transmitters, that are not FCC compliant, were used in the tests to simulate the impact of very high UWB device concentration. The measurement setup was organized to allow the UWB transmitters to generate as much interference to the WLAN n...

Ultra wideband (UWB) communications is a promising technology which provides high data rates for short-range communications. There are currently two proposals as UWB standards, namely, multiband orthogonal frequency division multiplexing (MB-OFDM) UWB and direct-sequence (DS) UWB. These two standards can cause interference on each other and also to other wireless technologies when they are loca...

چکیده: در این مقاله، یک آنتن جدید چهارتایی شکافی فشرده برای به­کارگیری در گیرنده­های gps ارائه شده است. ساختار آنتن از چهار عنصر تشعشعی شکافی نیم­طول­موج با یک نوار اتصال کوتاه تشکیل شده است که با اختلاف فازی 90 درجه نسبت به یکدیگر تغذیه می­شوند. ابعاد آنتن ارائه شده 3mm24î24î12 است که در مقایسه با بسیاری از آنتن­های ارائه­شده تاکنون بسیار کوچک­تر است. همچنین آنتن پیشنهادی دارای خلوص قطبش راست­...

Ultra wideband (UWB) technology based primarily on the impulse radio paradigm has a huge potential for revolutionizing the world of digital communications especially wireless communications. UWB provides the integrated capabilities of data communications, advanced radar and precision tracking, location, imperceptibility and low power operation. It is therefore ideally suited for the development...

This paper investigates the impact of chip duty factor (DF) in DS-UWB system with Rake receiver over AWGN and UWB indoor multipath environment corresponding to system parameters such as spreading bandwidth and chip length. Manipulating DF in DS-UWB system offers several advantages over multipath channel and thus, capable of improving system performance for better quality of communication. Altho...

The radio access technologies also presents the Coexistence issues between UWB and WiMAX systems at 3.5GHz frequency band which has been recently attained more attention. For investigating the potential interference of ultra-wideband (UWB) on a WiMAX system, an analysis method based on the physical layer modeling is presented. Multi-band orthogonal frequency division multiplex (MB-OFDM) UWB and...

This paper presents the performance of single band impulse radio systems, TH-UWB and DS-UWB, multiband impulse radio systems, MB-UWB, and multiband OFDM systems on the IEEE 802.15 UWB channel models CM1–CM4. The investigated impulse radio systems use approximately the spectrum 3–6 GHz and have a data rate around 100 Mbps. The DS-UWB system with a fractionally spaced Rake receiver with 10 finger...

We have considered multiuser communication scenario with ultra wideband (UWB) communication. UWB device is transmitting the data by time hopping (TH)-based system, TH-PPM, TH-PAM and DS-UWB. The UWB device is transmitting data over multipath rich channel model recommended by IEEE 802.15.3a working group. This channel model is based on Saleh-Valenzuela model. For better performance at receiver s...