Many predicted that the 10 millionth United States utility patent would be issued on June 19, 2018. Check. They also said it would be a high-tech invention. Check check. But they didn’t predict that the invention would seem more complicated than foreign policy.

The United States Patent and Trademark Office said Patent 10 million is for “Coherent Ladar Using Intra-Pixel Quadrature Detection.” The patent application lists the inventor as Joseph Marron of Manhattan Beach, California; the technology is owned by Raytheon Co. in Waltham, Massachusetts.

If you ever doubted the challenges of a patent examiner’s job, consider the following wording from the patent application describing this invention:

“A frequency modulated (coherent) laser detection and ranging system includes a read-out integrated circuit formed with a two-dimensional array of detector elements each including a photosensitive region receiving both return light reflected from a target and light from a local oscillator, and local processing circuitry sampling the output of the photosensitive region four times during each sample period clock cycle to obtain quadrature components. A data bus coupled to one or more outputs of each of the detector elements receives the quadrature components from each of the detector elements for each sample period and serializes the received quadrature components. A processor coupled to the data bus receives the serialized quadrature components and determines an amplitude and a phase for at least one interfering frequency corresponding to interference between the return light and the local oscillator light using the quadrature components.”

So, what is that?

Inventors Digest is happy to attempt a translation. First, what is ladar?

The best explanation we found is on Some sources (including Wikipedia) say that ladar is also called lidar, but that’s misleading because lidar uses light and ladar specifically uses lasers.

Ladar stands for LAser Detection and Ranging. Per sensorsinc: “Since the speed of light is well known, ladar can use a short pulsed laser to illuminate a target and then time how long it takes the light to return.

“The advantage of ladar over radar (Radio Detection And Ranging) is that ladar can also image the target at the same time as (determining) the distance. This allows a 3D view of the object in question. This provides long range reconnaissance with greater fidelity and thus greater recognition range than other technologies.”

The patent office says the invention has applications in fields that include autonomous vehicles, medical imaging devices, military defense systems, and space and undersea exploration.

So we know that the invention involves measuring distance via laser pulses, and in which fields it is commonly utilized. What about quadrature detection?

According to the RF Electronics engineering blog, a quadrature detector splits the signal that is to be demodulated into two signals. The first signal stays unchanged and is applied to the input of a phase detector. The second signal is passed through a capacitor.

If you’re lost at this point, join the club. The explanation goes on with terms such as phase shift and LC tank circuits. But give us credit for looking it up anyway.


Complexities aside, the simple point is that the milestone is a welcome celebration of a United States patent system that has had its struggles in recent years. Some Supreme Court rulings and the Patent Trial and Appeal Board have been under fire for being anti-patent. The United States has fallen to 12th in the most recent ranking of global patent systems.

But under Andrei Iancu, confirmed as USPTO director in February, there is a new optimism for the future of patents. The milestone patent was the first to be issued with a new patent cover design that was unveiled in March, adding symbolism for this fresh start.

What will the 11 millionth patent be for, probably three or four years from now? Given the furious technological pace we are setting in the United States (and throughout the world),   don’t bet against it being even more complex than this one.