Abstract: A radio (300) includes shielded circuitry (318) residing within radio frequency electromagnetic shielding structure (320) that has an aperture (322) formed therein. The shielded circuitry includes an optical transmitter (206) to direct light (information) through the aperture to an optical detector (208) coupled to other circuitry residing outside of the electromagnetic shielding structure. In this way, the optical detector receives light (information) from the optical transmitter via the aperture without degrading the radio frequency shielding of the shielded circuitry.

Abstract: A radio device (10) receives optical control signals from a remote control apparatus (22). In one embodiment, both the radio device and remote control apparatus include optical transmitters (58) and receivers (60) so that control and information signals may provided to and received from the radio's operator. In another embodiment, the radio () provides a light signal to the remote control apparatus () that either permits or prohibits (80) the light signal's return to the radio. In this way, the presence or absence of the return light signal comprises optical control signals to control the radio's operation.

Abstract: Printed circuit patterns are photolithographically defined on a three dimensional "projection" surface (204) of a printed circuit substrate (202) using a projection image aligner and a photomask (210) having a planar image (210A). The geometry of the projection is restricted such that the slope of the projection surface, as measured at any point on the projection surface and relative to a reference plane which is parallel to the focal plane of the projection image aligner, is less than 90 degrees. A solution of photoresist includes a photoresist solvent, a fluorosurfactant and an aromatic hydrocarbon solvent, and is preferably sprayed over the projection surface. In one method of manufacture, the printed circuit substrate is moved from one position to another during the exposure of the photoresist layer (206). In another method, after a first portion of the projection surface is exposed by a first photomask (502), a second photomask (504) is substituted and the remainder of the projection surface exposed.

Abstract: A light source (124) is used to transmit a light signal down an optical communication channel (12). In a light-reflective embodiment of the present invention, a portion of the transmitted light signal is reflected back (20) into the optical communication channel (12) to an optical receiver (126). By measuring the intensity of the reflected light, one or more operational parameters of the radio can be controlled (106). In a light-transmissive embodiment of the present invention a portion of the transmitted light signal is allowed to pass to the end of the communication channel. By measuring the intensity of the light reaching the end of the optical communicaton channel, one or more operational parameters of the radio can be controlled.