The analysts predict Apple will manufacture 91 million units of its three new iPhones during the latter two quarters of this year.
Apple sold around 46.7 million iPhones in the final quarter of 2017, - a figure bolstered by the November release of the iPhone 8, 8 Plus and X.
In their letter, the analysts said iPhone upgrades in recent years have been "below historical patterns."
This is due to handset "size, cost, [and] lack of differentiation from previous models."
The claim follows reports this year that sales of the iPhone X have been muted since its release last November.
This is in-part due to the handset's hefty price tag, with many consumers opting to stick with older models over forking out $1000 for Apple's flagship phone.
The tech giant has repeatedly denied sales of the iPhone X have failed to hit its sky-high standards.
Apple unveiled a 16 per cent sales surge to £44.9 billion ($97.6b) in May, but the firm sold fewer iPhones than hoped at 52.2 million, 300,000 less than experts expected.
The BlueFin Research experts believe cutting the iPhone X and iPhone SE this year will allow the company to focus on its new iPhones.
These handsets will address concerns that held customers back following the release of the iPhone X, according to Barron's.
The analysts believe the so-called iPhone 11 Plus will please users who found the iPhone X too small, while the iPhone 9 will offer a cheaper alternative.
It could replace 2016's iPhone SE, which was popular among Apple fans for its small size and reasonable price tag.
"The iPhone 11 Plus should satisfy those unhappy with the iPhone X due to size concerns, while the iPhone 9 device should satisfy more budget-conscious buyers and the aforementioned extension of the iPhone 8 model builds will round out a fairly extensive line-up," the analysts wrote.
They did not share information on what each of the new phones may offer, though rumours suggest the cheapest model - the iPhone 9 - will have an LCD display.
The iPhone 11 and 11 Plus could offer OLED screens.