'technology has been improved' is correct and usable in written English.
You can use it in any context where you are discussing current or past advances in technology. For example, "The efficiency of our communications systems has grown significantly in recent years, as technology has been improved."
The technology has been improved.
In this study pinch technology has been improved for wastewater temperature reduction.
The touchscreen technology has been improved to make it much easier to use the Surface Pro 3 as a replacement for a notebook and pen.
Although the technology has been improved, this review has identified problems in the construction and operation of Chinese biogas plants, particularly in the efficiency of household systems.
The fabrication process in superconductor normal metal superconductor (SNS) technology has been improved to raise the characteristic voltage of SNS active elements.
The motion capture technology has been improved, and widely used for motion analysis and synthesis in various fields, such as robotics, animation, rehabilitation, and sports engineering.
DNA sequencing technology has been improving by leaps and bounds in recent years, with several techniques vying for supremacy.
Although sequencing technology has been improving at a much faster rate than would be predicted by Moore's law (a prediction of improvement in computing hardware, but often also applied to other technologies), the technology for storing and analyzing the data has not seen a matching acceleration in improvement (Mardis 2010; Sboner et al. 2011).
Technology has been improving since the first tube was designed and built by Marconi.
With the development of smart grid, electrical equipment reliability and automation technology have been improved on large scale.
The ink manufacturing technology had been improved during the Eastern Han Dynasty, and the shape of ink had gradually developed into the large ingot-type, which can be ground directly against an inkstone.
