Apple's iPhone 5S will reportedly hit global stores between June and July this year, a new report said, indicating too that production of the hotly-anticipated smartphone will commence in full swing by March.

Quoting the new research note issued by Peter Misek of Jefferies & Co, Barron's reported that the next iPhone refresh will most likely come out rolling a few months from now.

"We see them as on track for a targeted June launch," Mr Misek said.

Should problems crop out, the rollout could be pushed back on July, the analyst said, quickly adding that for that to happen is slim at this point because there were "few changes for the iPhone 5S vs. the iPhone 5."

The latest note is almost positive that Apple is fully geared up for the iPhone 5S mid-year debut, even cutting down the production target of the iPhone 5 from 40 million units to 30 million in Q1 2013, though Mr Misek noted that the downgrade was partly caused by iPhone 5's "decelerating faster than expected."

Considering this troubling sales trend for Apple's flagship device, Mr Misek is convinced that Apple will opt for a simultaneous launch this year for two iPhone versions, with the company gunning to shore up what appeared as its smartphone's flagging sales performance.

To boost its sales, especially in the Asian market, Apple is partnering with China's China Mobile and Japan's DoCoMo. "We think the China Mobile launch will be focused on the low-cost iPhone while the DoCoMo launch will be focused on the 5S," the research note said.

But it's another story as far as the rumoured 4.8-inch iPhone 6 is concerned.

The supposedly iPhone phablet was originally scheduled for an October 2013 release but it will have to wait until early next year as Apple reportedly encountered production glitches in finalising the actual screen specifications of the larger iPhone.

"Our checks indicate that Apple's suppliers are running into difficulties trying to scale the screen size from 4-inch to 4.8-inch," Mr Misek said.

This particular iPhone 6 issue, he added, "is making Apple look at switching to on-cell (a different integrated touchscreen technology) and OLED (despite Apple's suppliers being well behind Samsung in their OLED capabilities) or IGZO."

Earlier reports have suggested that the tech giant is seriously considering the deployment of Sharp's IGZO display technology though many analysts believe that the option is more attuned for fitting into iPad and iPad Mini production.

According to BGR News, Apple could provide a glimpse of its fresh handsets via its annual Worldwide Developers Conference.