one-way RF signal diode
Yes.

There are two options for non-reciprocal devices, unfortunately neither is 'simple like a diode', they are an isolator, and a buffer amplifier. Schottky or PIN diodes will not do it, a switch made from them will conduct RF equally well in both directions when on. Attenuators and filters also behave in a reciprocal manner.

The first is a microwave isolator, though these are usually built with a circulator, with its third port terminated. These work over a narrow range of frequencies, in waveguide only, so you would need adapters to get to and from coaxial cable. The magnet can be big and bulky. They are relatively rare and expensive beasts.

The second is an RF buffer amplifier. These have the drawback of requiring power, but they can be very small, and are broadband, covering a wide range of frequencies. Being an active amplifier, they have a limited maximum power handling, add noise and generate distortion. In a pure reverse signal isolation mode, they tend to be used with an additional attenuator, that cancels their gain, and improves reverse isolation. They are available in a huge range from many manufacturers, most will just drop into a 50ohm system, and are relatively inexpensive.

In the very specific case of protecting a receiver from an adjacent transmitter, a limiter, usually made with PIN diodes, can offer a signal level dependent attenuation function. Note that is still not 'direction dependent' per se. For instance, a limiter might be designed to allow no more than +15dBm through it. A +40dBm transmitter will therefore suffer a nominal 25dB attenuation, whereas the receiver signal will not be attenuated.