Design a MIMO printed dipole antenna for 5G sub-band applications

YesIn this paper, a planar multiple input, multiple output (MIMO) dipole antenna for a future sub-6 GHz 5G application is proposed. The planar MIMO structure consists of 4 antenna elements with an overall size of 150×82×1 mm3. The single antenna element is characterized by a size of 32.5×33.7×1 mm3 printed on an FR-4 dielectric substrate with εr=4.4 and tanδ=0.02. The suggested antenna structure exhibits good impedance bandwidth equal to 3.24 GHz starting from 3.3 to 6.6 GHz with an S11 value of less than -10 dB (S11≤-10 dB) with antenna gain varying from 5.2 up to 7.05 dB in the entire band, which covers all the sub-6 GHz frequency band of the 5G application. Good isolation is achieved between the MIMO elements due to low surface waves inside the MIMO antenna substrate. The radiation of the MIMO antenna structure can be manipulated and many beam-types can be achieved as desired. The high-frequency structure simulator (HFSS) software package is used to design and simulate the proposed structure, while the CST MWS is used to validate the results

Role of the renal sympathetic nervous system in mediating renal ischaemic injury-induced reductions in renal haemodynamic and excretory functions

Methods: Anaesthetised male Sprague-Dawley rats were subjected to unilateral renal ischaemia by clamping the left renal artery for 30 min followed by reperfusion. Following acute renal denervation clearance experiments were performed. In a different set of experiments, the renal nerves were electrically stimulated at increasing frequencies and responses in renal blood flow and renal vascular resistance were recorded. Results: Denervated post-ischaemic acute renal failure (ARF) rats showed higher urine flow rate, absolute and fractional sodium excretions, urinary sodium to urinary potassium, glomerular filtration rate and basal renal blood flow but lower basal renal vascular resistance (all p 0.05 vs innervated ARF rats). The rise in mean arterial pressure and renal vasoconstrictor response to renal nerve stimulation were blunted in denervated ischaemic ARF rats (all p < 0.05 vs innervated ARF rats). Renal histopathology in denervated ARF rats manifested a significantly lower medullary congestion, inflammation and tubular injury compared to innervated counterparts (p < 0.05 vs innervated ARF rats). Conclusions: The findings strongly suggest the involvement of renal sympathetic tone in the post-ischaemic events of ischaemic ARF, as the removal of its action to a degree ameliorated the post-ischaemic renal dysfunctions