Circularly Polarized Conical Beam Formation by Backfire Helical Antennas

A backfire helical antenna (BHA) is numerically analyzed to form a circularly polarized conical beam. The conical beam whose radiation is null in the helical axis direction is obtained using the second mode operation of the BHA. The characteristics of monofilar, bifilar and quadrifilar BHA\u27s are compared and discussed. It is found that a second-mode bifilar BHA radiates a circularly polarized conical beam over a frequency range of 1 : 1.4. The use of the first mode of a bifilar BHA is also investigated to form a quasi-conical beam which has the weak radiation in the helical axis direction

Long-term safety and efficacy of benralizumab in patients with severe, uncontrolled asthma: 1-year results from the BORA phase 3 extension trial

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