• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.61-64
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• 2017

A phase shifter is one of the key components that change the phase of an individual antenna in millimeter-wave phased array system. This paper presents a low-loss phase shifter design with two parallel 2-state amplifiers. To get the same gain of $0^{\circ}/180^{\circ}$ each state, delay lines are in the middle of each stage of the 2-Stage amplifiers. Normally, when adding AMPs in parallel, a power combiner/divider such as Wilkinson Power Combiner/Divider is added, but they are directly connected because it can cause added losses in silicon wafer. The measured data shows 12dB gain and 174-degree phase difference at 5GHz.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.85-88
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• 2001

In this paper we consider a problem of blind co-channel signal separation, the goal of which is to estimate multiple co-channel digitally modulated signals using an antenna array. We employ the joint maximum likelihood estimation and present a sequential algorithm, which is referred to as sequential joint maximum likelihood (SJML) algorithm. It separates multiple co-channel signal on-line and converges fast in overdetermined noisy communication environment. And the computational complexity of SJML for M-QAM (M=8, 16, 64,...) signals is less expensive compared to the SLSP. Useful behavior of this algorithm are confirmed by simulations.