• OpenAccess
    • List of Articles Wideband

      • Open Access Article

        1 - A Wideband Low-Noise Downconversion Mixerwith Positive-Negative Feedbacks
        Hadi Naderian Ahmad Hakimi
        This paper presents a wideband low-noise mixer in CMOS 0.13-um technology that operates between 2–10.5 GHz. The mixer has a Gilbert cell configuration that employs broadband low-noise trans conductors designed using the negative-positive feedback technique used in low-n More
        This paper presents a wideband low-noise mixer in CMOS 0.13-um technology that operates between 2–10.5 GHz. The mixer has a Gilbert cell configuration that employs broadband low-noise trans conductors designed using the negative-positive feedback technique used in low-noise amplifier designs. This method allows broadband input matching. The current-bleeding technique is also used so that a high conversion gain can be achieved. Simulation results show excellent noise and gain performance across the frequency span with an average double-sideband noise figure of 2.9 dB and a conversion gain of 15.5 dB. It has a third-order intermodulation intercept point of -8.7 dBm at 5 GHz. Manuscript profile
      • Open Access Article

        2 - An Ultra-Wideband Common Gate LNA With Gm-Boosted And Noise Canceling Techniques
        Amin Jamalkhah Ahmad Hakimi
        In this paper, an ultra-wideband (UWB) common gate low-noise amplifier (LNA) with gm-boosted and noise-cancelling techniques is presented. In this scheme we utilize gm-boosted stage for cancelling the noise of matching device. The bandwidth extension and flat gain are a More
        In this paper, an ultra-wideband (UWB) common gate low-noise amplifier (LNA) with gm-boosted and noise-cancelling techniques is presented. In this scheme we utilize gm-boosted stage for cancelling the noise of matching device. The bandwidth extension and flat gain are achieved by using of series and shunt peaking techniques. Simulated in .13 um Cmos technology, the proposed LNA achieved 2.38-3.4dB NF and S11 less than -11dB in the 3.1-10.6 GHz band. Maximum power gain (S21) is 11dB and -3dB bandwidth is 1 .25-11.33 GHz. The power consumption of LNA is 5.8mW. Manuscript profile
      • Open Access Article

        3 - A Survey of Two Dominant Low Power and Long Range Communication Technologies
        Yas Hosseini Tehrani Seyed Mojtaba Atarodi ZIba Fazel
        The Internet of Things (IoT) connects various kinds of things such as physical devices, vehicles, home appliances, etc. to each other enabling them to exchange data. The IoT also allows objects to be sensed or controlled remotely and results in improved efficiency, accu More
        The Internet of Things (IoT) connects various kinds of things such as physical devices, vehicles, home appliances, etc. to each other enabling them to exchange data. The IoT also allows objects to be sensed or controlled remotely and results in improved efficiency, accuracy and economic benefits. Therefore, the number of connected devices through IoT is increasing rapidly. Machina Research estimates that the IoT will consist of about 2.6 billion objects by 2020. Different network technologies have been developed to provide connectivity of this large number of devices, like WiFi for cellular-based connections, ZigBee and Bluetooth for indoor connections and Low Power Wide Area Network's (LPWAN) for low power long-distance connections. LPWAN may be used as a private network, or may also be a service offered by a third party, allowing companies to deploy it without investing in gateway technology. Two available leading technologies for LPWAN are narrow-band systems and wide-band plus coding gain systems. In the first one, receiver bandwidth is scaled down to reduce noise seen by the receiver, while in the second one, coding gain is added to the higher rate signal to combat the high receiver noise in a wideband receiver. Both LoRa and NB-IoT standards were developed to improve security, power efficiency, and interoperability for IoT devices. They support bidirectional communication, and both are designed to scale well, from a few devices to millions of devices. LoRa operates in low frequencies, particularly in an unlicensed spectrum, which avoids additional subscription costs in comparison to NB-IoT, but has lower Quality of Service. NB-IoT is designed to function in a 200kHz carrier re-farmed from GSM, with the additional advantage of being able to operate in a shared spectrum with an existing LTE network. But in the other hand, it has lower battery lifetime and capacity. This paper is a survey on both systems. The review includes an in-depth study of their essential parameters such as battery lifetime, capacity, cost, QoS, latency, reliability, and range and presents a comprehensive comparison between them. This paper reviews created testbeds of recent researches over both systems to compare and verify their performance. Manuscript profile