very thin glass sheets are used to form these

Question

Very thin glass sheets are used to form these capacitors. The sheets are interleaved with aluminium foil and fused together to forms a solid block. These capacitors are smaller in size compared to encased mica capacitors and can be operated at very high working voltages. Their capacitance stability and Q are very constant. These capacitors have an advantage that they do not need additional casing. Glass itself acts as casing. These capacitors are light weight, have low losses, high insulation resistance and high breakdown strength.

Specifications

Range of values          150pf to 10000pf

Voltage rating                                                                    300V to 500V

Temperature coefficient                                                       -55⁰C to +200⁰C

Applications: used in medium power transmitters.