The first half of 2022 has been very challenging for XP Power, like many other companies in our industry. There's been macroeconomic challenges, there's been component challenges, and to be honest, resulted in a disappointing financial result. We haven't been able to source the level of components that we would normally, and that's an industry-wide factor. Now, what we have done, we've been sourcing them as much as we can. We've been working with customers to redesign products, but inevitably has held back revenue in the first half. The second factor was COVID has reared its head again. Our factory in China, in Kunshan, was shut down for five weeks in April. During that period, we had no production coming out of China. We've retained all of the team there, but it has limited our revenue in the first half.
The site is now running at full steam, and we're confident it will deliver performance for the second half. Global logistics has been a problem for everybody, still recovering from impact of COVID. We've had to move more shipment to air freight just because the lead times required. It's put additional costs onto us that we've had to absorb or pass on to customers where appropriate. The other challenge we've had, we're involved in a court case in the U.S. during the first half. It was a jury trial and resulted in damages payment. We're still waiting for the ruling from the judge, so at this stage, very limited things I can say about that issue. Despite the financial results, we've had exceptional demand ongoing for our products.
We've added two additional companies to the portfolio, two German high-voltage businesses, which we're very excited about that high-voltage business we're building. Operationally, we've made real progress during the first half to give us confidence in a much better financial performance in the second half of the year.
In constant currency, orders were up 18%, which is very encouraging, at GBP 193 million. Unfortunately, revenue was down 1%, and that's really a reflection of the challenges we faced in the first half of the year. The challenges which were really down to the component shortages, the shutdown of COVID in China, that resulted in volumes being a lot less going through our factories. The impact of those volumes also had a margin impact on us, and gross and operating margins were clearly impacted by the lower volumes that have come through our factories. They were also compounded by inflationary challenges as well as the global logistics challenges that we face across the group. That brought the gross margin from 46.6% down to 40.2%.
The net debt has increased as a result of quite a number of major investments. We bought the businesses that Gavin mentioned at the beginning, and we've invested materially in inventory to be able to manage the revenue demand that we see coming in the next few months. We've declared a dividend, which is very encouraging for our shareholders, to be paid in quarter three. It just shows the confidence that we have in the longer- term of the business.
Demand for our product continues to be strong across all three sectors that we focus on. Industrial technology, for us, it's driven by innovation. It's things like precision equipment, analytical equipment. It's high-end computing. It's comms. So it's a very, very diverse sector, and we're seeing demand from all aspects of that part of the business. On healthcare, our customers, they've got very strong order books, and with the recovery of operational procedures in hospitals, there's demand for many robotic products or anything in the operating theater, and that's driving demand for our products, and we see that going forward through 2022 into 2023. Finally, the semiconductor manufacturing equipment sector has continued to be very strong. You may have read about demand dropping for PCs. That hasn't impacted us at all yet, and we don't see it doing so going forward.
What we're seeing is this, despite the drop-off, there's still lack of capacity for semiconductors. The fabs going in, the equipment that's going into them is still driving very strong demand. That's driving demand for our products from our customers.
We've seen demand in the industrial technology sector grow GBP 6.7 million, over 6% in the first half of the year. This is very encouraging for us. In terms of semiconductor, the demand has remained very strong, and we see the growth increasing by GBP 2.1 million in the first half of the year, at another 3% growth on top of where we were a year ago. In terms of healthcare, we've seen demand increase by 45%, over almost GBP 13 million of where we were last year.
Sustainability is part of XP Power's DNA, and has been for many, many years. Our intent is to lead our industry in this area. During the first half of the year, we've been doing a full mapping of our scope 1, scope 2, and scope 3 carbon footprint, and on the back of that, we've signed up to the Science Based Targets initiative as we set out commitments going forward. We've very publicly said we want to be carbon neutral by 2040, and as part of the Science Based Targets, we'll be releasing interim targets that we would look to meet probably around the 2030 area. It's not all about sustainability. It's been a very challenging period, as we said, and our people are key to supporting our business.
We've been focusing on mental wellness, making sure they feel supported, and we as a company support them in what they need to do.
We continue to invest in people, systems, and infrastructure. Again, very exciting for the future of the business. We're talking about engineers, we're talking about salespeople, and the investment in capacity is essential for delivering the growth in the future. We're investing in a factory in Malaysia and a design engineering center. We've rolled out our Enterprise Resource System, our ERP system, SAP S/4HANA, across the group, and particularly now in Asia, the manufacturing sites have been put onto the system. This is gonna bring us huge benefits in terms of being able to manage our supply chain better as we go forward and be able to manage growth going into the future.
Medium term and long term, we are very, very confident. We start the second half of 2022 with a signed order backlog of GBP 285 million, up from GBP 217 million at the beginning of the year, and that gives us confidence of our performance for the second half. We expect continued strength in each of our sectors, driving good demand for our products. The supply chain challenges across logistics, across component shortages will abate, and that will ensure we deliver much stronger financial performance in the second half. We see the business being far larger going forward, and we're putting an infrastructure in place to support that growth to make sure we can deliver effectively for our customers.